Nickel in blocks???

[iluv69s]

Saw this on FB.. varying replies as if it is an urban legend.

Anyone know the real deal?

[William]

One of the CRG Core members asked the same question years ago. The late John Z's response:

NOPE.

"Most people have no clue how a high-volume foundry operates - the "recipe" for the grey iron and malleable iron melt load wasn't changed; it was very carefully arrived at over the years, and its content was stabilized. The "high-nickel block" theory was debunked years ago, although some folks still cling to it."

John

[Too Many Projects]

Very interesting, I've always heard about the 010 block being high nickel too.
So, does anyone know what the 010, 020 509 indicate on a block ?

[jer]

Last three digits of the part number, the block applies to 3 variants on this one.

[70 copo]

Well this can be tested. Get a 307 casting and drill into it and you will see how soft the casting is compared to the same year 010 302/350.

Start there.

Casting numbers are different due to changes in metallurgical content and design.

[69 Post Sedan]

Last three digits of the part number, the block applies to 3 variants on this one.

This makes sense…..and what I assumed for years.

3970010
3970020
3951509

Kurt

[70 copo]

Yep. and why the need for variants??

[70 copo]

Nearly all 010 castings from the mid 1970's onward were all "010" for all HP designations. Why were there basically no variants after hi compression was dropped?

[MarcDant]

Better yet just have a metal composition analysis preformed, it will tell you all you need to know about the high nickel block, after all they did cast the harder ductile main bearing caps. So the material was there.my .002 cents.

[70 copo]

Recall all those kids that did budget builds on 307's by overhauling them with higher compression pistons?

Neither do I.

[bergy]

I'm a metallurgist and was superintendent of the melt department at the Tonawanda metal casting plant. Jon's statement was true. We ran all 4 of our cupolas with the same chemistry base iron. We were producing about 2,500 tons of iron a day - feeding 7 molding lines, so as a practical matter, it would have been impossible to route different base irons to different lines in production. Alloying with ferro-chromium and silicon was performed as the iron was poured into the hot metal crane ladles (these cranes traveled on monorails that transported the molten iron to the individual molding lines). All lines received silicon (a late alloying agent designed to refine the grain structure of the cast iron by providing more grain nucleation sites and reducing carbide formation). Ferro-chromium was only alloyed into the lines that produced blocks (mold line 1 & 2 at Tonawanda). It was added to promote pearlite formation which increased the tensile strength of the cast iron. You may ask - then why wasn't ferro-chromium added to metal being delivered to all of the lines? the reason is that chromium can cause carbides to form in thin sections of casting. The cutting tools at the motor plants would not like this, so chromium was only added to blocks where increased tensile strength was required (class 30 gray iron). The chrome content in class 30 iron was targeted at .032 %.

Just food for thought - nickel is also a strong pearlite stabilizer and would increase the tensile strength of cast iron (similar to chrome, but without the tendency toward carbide formation). Ferro-chromium (not metallic chromium) is a relatively cheap commodity, and, therefore, a good choice for alloying in a high production environment. In smaller job shops - nickel alloying could be used to increase tensile strength in cast iron. In these low production environments - the shop may not want to risk the carbide formation tendency of ferro-chromium. So - this is just conjecture - over the years people familiar with job shop practices may have assumed that nickel was being used in high volume environments.

[cook_dw]

Very informative post. Thank you for clarifying the process Bruce.

[Jonesy]

That is an urban myth. The last 3 numbers of the casting were typically cast in both front (area under timing cover) and rear (area covered by the bellhousing) of block. 3970010 have the 010 and 020 because they are last three numbers of blocks in that casting timeframe. The 3970010 and 3970020 blocks.

You will also see this on small blocks made throughout the 60's.
1967 3892657 blocks have 657 and 944. (3892657 and 3896944)
Some 1965 3782870 blocks have 870 and 721. The 3790721 was the predecessor.
So it was a foundry thing to do this.


Its just a coincidence that the 010 and 020 blocks ended in those numbers.

[bergy]

I agree - front and rear housing cores were common among several part numbers. Every time a casting was modified, a new part number was supposed to be assigned, but if the change didn't involve the front or rear casting face - the same old housing core boxes would be used. These front and rear housing cores were made on equipment that was the oldest at Tonawanda. The binder used was actually a derivative of linseed oil. The dimensional tolerance capability of these "oil sand" cores was not great, so it was gradually being phased out in favor of phenolic urethane binders. the "oil sand" front and rear housing core boxes were very old & were used for multiple part number blocks over the years.

[RALLY]

One of the CRG Core members asked the same question years ago. The late John Z's response:

NOPE.

"Most people have no clue how a high-volume foundry operates - the "recipe" for the grey iron and malleable iron melt load wasn't changed; it was very carefully arrived at over the years, and its content was stabilized. The "high-nickel block" theory was debunked years ago, although some folks still cling to it."

John

If anyone knew, it was the late great John Z. I asked him numerous questions about Chevy SB Heads and he always answered my emails.

[Lynn]

Recall all those kids that did budget builds on 307's by overhauling them with higher compression pistons?

Neither do I.

Most 307 castings did not get hot rodded because of the small bore size, and they are all two bolt main. Although four bolt mains aren't essential, they are so prevalent and cheap, most folks would prefer to start with a 4 bolt block.

"One interesting fact regarding the Chevy 307 V8 was that it was also manufactured by GM for boat use and sold by the Outboard Marine Corporation as a high performance marine engine. The marine version of this engine produced between 235 and 245 horsepower and even used the same aluminum valve covers that were used in Corvettes and Camaro Z-28s." Quoted from this article: https://www.enginefacts.com/chevrolet307/

Don't know about "kids", but many others have use 307s as a starting point with good results.

https://www.onallcylinders.com/2021/11/18/long-rod-chevy-307-big-power/

https://www.motortrend.com/how-to/sucp-0604-chevy-engine-performance/

https://www.onallcylinders.com/2020/09/04/ask-away-with-jeff-smith-getting-the-best-of-a-chevy-307-without-blowing-it-up/

[70 copo]

Ok for the sake of discussion. Bergy:


Why were the later 010’s all the same after the mid 1970’s?

2 bolt mains and 4 bolt mains?

[70 copo]

And I just called a local guy who has overhauled engines fir a living for decades

The metal is definitely softer on the later blocks.

Explain please.

[70 copo]

And as an additional bonus isn’t it true that a flint block could be built as a lower horse motor but not the other way around?

How many LT-1’s 302’s were cast in NY??

[bergy]

Phil - I don’t want to argue. You always draw your own conclusion anyway :-)

[70 copo]

Phil - I don’t want to argue. You always draw your own conclusion anyway :-)

Not trying to Argue.

Can you address the questions posed given your stated expertise?

[MarcDant]

This is from the camaro brochure.

[bergy]

So, you called a machinist who has determined that the brinell hardness reading is greater on later blocks? 😂

Do you know how silly that sounds? All you want to do is argue. PM me if you really have questions.

Quantitative hardness testing on a representative sample of blocks cast on specific dates would be the only way to draw conclusions. I lived this Phil - please don’t just be contrary. PM me if you have questions.

[70 copo]

So, you called a machinist who has determined that the brinell hardness reading is greater on later blocks? ��

Do you know how silly that sounds? All you want to do is argue. PM me if you really have questions.

Quantitative hardness testing on a representative sample of blocks cast on specific dates would be the only way to draw conclusions. I lived this Phil - please don’t just be contrary. PM me if you have questions.

Perfect!

Now with that aside the Marc Dant post is instructive as to the discussion for those so inclined.

[bergy]

The brochure must refer to casting design enhancements. Class 30 cast iron for blocks was metallurgically unchanged.

[70 copo]

The brochure must refer to casting design enhancements. Class 30 cast iron for blocks was metallurgically unchanged.

Two apparent distinct and separate references.

One to a tougher block. The other to 4 bolt main caps.

[70 copo]

As an aside I have a detailed Early and later 010 design comparison changes for blocks in images... I can post here if there is interest.

[bergy]

I’m just telling you facts Phil. Your “apparent” conclusions are on you :-)

[Andy]

Bergy,, I have a question. I’ve always heard that 2 freeze plug, 2 bolt main 400 small blocks were better/stronger/heavier castings than the 3 freeze plug 2 and 4 bolt main versions. So I built my 406 with the two freeze plug casting. Can you shed any light on this? I’d appreciate hearing your feedback.

[bergy]

When I don't know I'll tell you Andy - I don't know the answer to your question. As I recall, there was a 400 block that ended in 817 during the 70s. We all felt that it was the highest quality block that we produced. It was the only block that was cast using a single core to form all of the bores and bulkheads. So, it was a lot more dimensionally accurate then the multiple cylinder bore cored blocks.

[hogdaddy]

Here's some good (debatable) reading on that subject

http://garage.grumpysperformance.com/index.php?threads/splayed-main-caps.1014/

[I think the 400 SBC 4 bolt blocks have a bad reputation that's probably not fully deserved , the rumor is that the web area of the block is weaker and the outer bolts further weaken the block, but I think its more a case of the extra bolts don,t significantly add to the block rigidity .
the 350 and 400 SBC OEM production blocks were designed to handle 350-400hp max,and when pushed well past that stress level its just logical that they occasionally fail.
if a two bolt block fails the normal response seems to be that
'we should have installed the angled aftermarket main caps'
if a four bolt block fails the normal response seems to be that
'we should have installed the angled aftermarket main caps, because the damn four bolt blocks weaker'
the truth is that by the time your making 500hp neither block with stock main caps keeps the main caps from moving under full loads and adding the splayed main caps while helpful is not a cure, its a band-aid at best, the aftermarket DART block has much thicker castings in the block web area and better and stronger alloys used.]

[70 copo]

A direct quote from the Link: http://garage.grumpysperformance.com/index.php?threads/splayed-main-caps.1014/

"failure to check for cracks or use of a O.E.M. block at power levels its not designed for can and frequently does result in engine failure,

Most O.E.M. SBC blocks are rated at no more than 400hp, we all know guys pushing them to 500hp but much beyond that its a crap shoot and the blocks eventually going to flex and fail".

Now why would "Most" SBC blocks eventually "Flex and Fail"??

400-500 HP is not a known problem on 302's or LT-1's as far as flex correct?

[all_about_cars]

386,388,618 and 010 blocks weren't cast specialty for 302,327 or 350. They were just blocks that didnt become 302 or LT1 until assembly so I would say yes they would have the same problem as any other block. I've seen more than one block machine shop didn't want to use because of poor casting like center line being off. Also plenty with main caps that were loose and moving around.

[70 copo]

Before we begin some commentary. At the risk of additional insults we will attempt to examine factual information. This is supposed to be the premiere Muscle car site right? So guys why not hold the "circle the wagons" stuff for a bit. The moderators/Administrators have been alerted to the conduct in the thread to date - and have done zip to address it - so I will address it with information and evidence.

If all of you are the "experts" on this you will be able to debunk everything I am about to post. However substituting insults in leu of a factual argument is quite self evident, so please be respectful and so will I.

Lets begin.

[70 copo]

The Story as we know it:

Nickel was used to harden the bore surfaces so the ring seal is better. Tin was used to make the block heat and cool more evenly. Tin and Nickel are shown as percentages in numbers cast into the block under the timing chain cover.

A "high nickel" block will have either "010" or "020", which indicates 10% and 20% nickel, accordingly.

The best blocks have both tin and nickel, and show two numbers: 010 and 020, which means the block has 10% tin and 20% nickel.

Some of the the early 400 SBC were also 010 and 020 cast and quickly became the go to choice for the circle track racers because they held up and dominated the track conditions the aftermarket followed and that motor became the go to engine for that kind of racing.

[70 copo]

When I say 302 and LT-1 I am specifically referring to the 010 casting of both and 010 castings produced in Michigan.

FORD had the Windsor then they had the Cleveland These were technically different block designs and as we will soon see GM did the same thing with the 010 changing the design at least 3 times while keeping the same casting number.

I asked about this. I was told that these subtle changes were accomplished to at first to transition the engine from a high compression centric design then later again to adapt the block to better meet durability and emissions as GM moved to a corporiate engine usage format. These later 010's are the two bolt variants and are easily recognizable by the small pad where the usage designation was stamped which was shared by the 305 also.

[70 copo]

The evidence:

[70 copo]

Look at the design. Casting is different.

[70 copo]

More:

[70 copo]

Another:

[70 copo]

Even More:

[70 copo]

And More:

[70 copo]

Mains:

[70 copo]

Filter area:

[70 copo]

Front

[70 copo]

Design differences and reinforcements on the 1969 block.

[70 copo]

In conclusion. Yes I have looked into this just like I did with the two books I wrote on the Norwood Plant. A comment made by the Norwood Superintendent "for those guys"

"Funny that None of us at Norwood can recall anything about what we did in plant yet someone who worked in another GM plant makes a claim and everything he says is gospel on that forum. Yet the extensive research you did which is very factual is usually dismissed out of hand. Jealousy is a bad thing as well as partisanship".

So with that said gentlemen lets discuss this like gentlemen shall we? Unless you are going to claim the images are "fake "what I have presented is self evident.

So what do we have here? What are we looking at? I have presented EVIDENCE. Opinions are ok but an opinion should not be framed as evidence.

"Silly" I am not. I am quite serious.

[dustinm]

I thought the question at hand was nickel content, not structural integrity of the casting??

[70 copo]

Well we can try to get to the bottom of this. If the basic block design varies then the metallurgical content can also vary that makes sense. Also both blocks are flint cast. and as we know Hi performance flint blocks were the blocks used for the high winding engines during that period.

[Lynn]

Two apparent distinct and separate references.

One to a tougher block. The other to 4 bolt main caps.

That promo was written long before they even cast an 3970010 block which didn't show up until the last part of April, 1969. "Tougher" could just be referring to a design change where some part of the block was beefed up.

I don't have a dog in this hunt, so it really doesn't matter one way or another to me.

Phil, are you saying there is credible evidence that "The best blocks have both tin and nickel, and show two numbers: 010 and 020, which means the block has 10% tin and 20% nickel."???

I don't believe anyone disputes there were a lot of design changes. If you have some GM documentation on the percentage of tin and nickel, I would be interested in seeing it. Just post it.

[70 copo]

That promo was written long before they even cast an 3970010 block which didn't show up until the last part of April, 1969. "Tougher" could just be referring to a design change where some part of the block was beefed up.

I don't have a dog in this hunt, so it really doesn't matter one way or another to me.

Phil, are you saying there is credible evidence that "The best blocks have both tin and nickel, and show two numbers: 010 and 020, which means the block has 10% tin and 20% nickel."???

I don't believe anyone disputes there were a lot of design changes. If you have some GM documentation on the percentage of tin and nickel, I would be interested in seeing it. Just post it.

Yes showing respect is uncomfortable.

Right now Nobody wants to take a position because they are hedging that I could be holding back.

Ball is in your court guys. You watched a member here openly mock me which is the normal progression of things as the flame war that started nearly 10 years ago continues.

Lynn you are a Lawyer. When one side makes a motion you are rule bound to reply.

You do not get to question me further on my submittal because absent a credible argument the other reply is “gee Phil we jumped to conclusions and we are sorry”.

A non reply on the other hand admits my position as the fact

[Too Many Projects]

You do not get to question me further on my submittal because absent a credible argument the other reply is “gee Phil we jumped to conclusions and we are sorry”.

A non reply on the other hand admits my position as the fact


OBJECTION !!! Badgering the witness, PHIL
NO ONE is going to reply because we are all sick and tired of your bullying, badgering insistence on being right.
It has become PAINFULLY obvious that you will not quit until others do and you can feel self justified that you WIN...
Silence is not winning, it's just the rest being tired of your tactics.



Are you holding back ????????????

If so, the cards are on the table and now it's YOUR turn to show your hand of aces. If you have credible, documented PROOF to back up all your conjecture and smoke, we're ALL waiting to see it.


If not, then it's well past time for you to agree to disagree and stop the badgering to get your way.

[70 copo]

OBJECTION !!! Badgering the witness, PHIL
NO ONE is going to reply because we are all sick and tired of your bullying, badgering insistence on being right.
It has become PAINFULLY obvious that you will not quit until others do and you can feel self justified that you WIN...
Silence is not winning, it's just the rest being tired of your tactics.



Are you holding back ????????????

If so, the cards are on the table and now it's YOUR turn to show your hand of aces. If you have credible, documented PROOF to back up all your conjecture and smoke, we're ALL waiting to see it.


If not, then it's well past time for you to agree to disagree and stop the badgering to get your way.

Mitch,

Calm down and look through the thread. Where is the information that I posted that is wrong or incorrect ?

Your reply looks like an attempt to get the thread locked or entirely deleted.

Not good.

[jeffschevelle]

I have no idea about the original question and no dog in the fight. But it is very obvious to me that pictures of casting differences between a 1973 and a 1969 block don't have one single thing to do with what the metal content of either of those blocks is or is not. For example, 1965-66 396 blocks (both 961 and 962) carry the same casting numbers and part numbers across both years, but there are numerous significant casting differences between early 65 396 blocks and 66 396 blocks. That does not mean the metal content was any different. Maybe after 4 years the content was different, maybe it wasn't. But casting differences have nothing to do with that question.

And if I was going to weigh evidence and render a judgment (continuing the courtroom theme started earlier), I would find it very easy to believe the guy who is "a metallurgist and was superintendent of the melt department at the Tonawanda metal casting plant." Is anyone else posting in this thread a metallurgist? Is anyone else posting in this thread a former SUPERINTENDENT of the melt department at the Tonawanda metal casting plant (not just a low level laborer, but a SUPERINTENDENT)?

This is not the same as the silliness of an assembly line worker claiming he remembers what head marking was on a screw he installed on a certain Wednesday in between punching the clock to get his paycheck 50+ years ago. I find it hard to conceive of anyone who would be any more likely to know what the metal content of a casting was than the person who was "a metallurgist and superintendent of the melt department at the metal casting plant" at the time in question.

So what am I missing here ??

[bergy]

Phil - Don Quixote has nothing on you!

That's a lot of research to prove that:

- there were 12 stations at the oil sand oven where front and rear housings cores were produced. 6 International machines for front housings and 6 International machines for rear housings. So, that means 6 DIFFERENT core boxes for each housing (plus the spare core boxes up in the pattern storage area on the second floor. Not every core box was identical due to repairs and cosmetic changes made over the years. this same explanation applies to changes in the filter bowl set core area (only there were 24 individual inserts plus spares). Ditto for the cope and drag patterns where there were 3 of each (plus spares).

The flow off scar on the top rail is an addition to the patterns that I HAD MADE. There was a problem with gas accumulating at the top of the rail during mold fill. We added those pins to help the gas escape better.

anyone who thinks we added 10-20% nickel to gray cast iron isn't just silly.

[COPO]

The Story as we know it:

Nickel was used to harden the bore surfaces so the ring seal is better. Tin was used to make the block heat and cool more evenly. Tin and Nickel are shown as percentages in numbers cast into the block under the timing chain cover.

A "high nickel" block will have either "010" or "020", which indicates 10% and 20% nickel, accordingly.

The best blocks have both tin and nickel, and show two numbers: 010 and 020, which means the block has 10% tin and 20% nickel.

Some of the the early 400 SBC were also 010 and 020 cast and quickly became the go to choice for the circle track racers because they held up and dominated the track conditions the aftermarket followed and that motor became the go to engine for that kind of racing.

I have no real knowledge of the block difference, however, I do find it hard to believe these high percentages of Tin and Nickel. Perhaps 1% and 2% is more accurate.

[70 copo]

Bergy,

Good. Progress.

So far Where in this thread did I offer anything stating that the Nickel/Tin thing was 100% real?

Note: I didn't.

Many here are basing their informed opinions on the fact that the blocks were "all the same."

Are they? How does this relate to .10/.20?

Start there.

[Lynn]

Phil: I can't admit your position as fact if I don't even know your position.

I can't tell from any of your posts if you believe the 010 blocks have higher tin and nickel content.

[70 copo]

Fair enough. I appreciate your candid reply.

Just so you know I have complete understanding of all the positions taken here and unlike you I understand them.

In order to even reach a discussion point one of these sides is going to need to entertain the idea of a radically different position.

My position that the blocks were different is supported with evidence.

Ball is still in your court guys.

[Lynn]

I'm no good at riddles; I am out.

[MarcDant]

Got no pup in this litter,I know this sounds extreme but as mentioned earlier have a metal composition analysis done between blocks in question (2 small samples of material off each block & compare) at NSL ANALYTICS CLEVELAND OHIO, my former employer & their affiliates used to use $300 - $500. There’s also infinita lab in California I will chip in, not trying to be smart SSA. Thanks Marc

[Steve Shauger]

Lets be respectful to one and other. It's a slippery slope when a theory is purported as fact. I don't want to squelch debate, but facts need to be introduced to support them or mis-information turns into myth and later fact.

I do believe the casting #'s represent running changes for strengthening, manufacturability and various improvements, which are documented with examples. Regarding block material being identified by casting identifiers... well this is completely unproven. We have two notable authorities (John Z. & Bergy) who have firsthand intimate knowledge and have debunked the nickel and tin content variants based on application theories as it relates to Chevrolet built engines.

[70 copo]

Lets be respectful to one and other. It's a slippery slope when a theory is purported as fact.

Steve,

I am curious to ask .. Are the images I posted both real and authentic small blocks?

What is your take on this specifically?

Are these images and what they show a "theory"?

[camarojoe]

Let me start by saying i don't know anything about this topic, nor am I taking sides on the matter...but from what i can tell the images simply show changes to the outward appearances of the blocks over the years, small casting details, etc... How do any of the photos show the actual composition of the iron the blocks were cast from was ever changed? From what I can see, they don't. It would be like posting pics of 67 and 68 camaro fenders and saying because there are outward visible differences, the composition of steel itself must have changed.

[turbo69bird]

We have this same debate w Pontiacs the c118 RAII block is the only as cast 2506 block the rest were 9790071 and they ground off and stamped the rest of that 2506 number. this has led to a debate about that being a high nickel block. Some RAII race cars had that block moved to the next seasons car as they were both considered 2506 blocks NHRA allowed it. Speculation was that it must be Because it was high nickel . (The story the driver gives is it was already balanced and blueprinted and was considered the same block ) saved money.
A few months back I posted a few outward anomalies in the blocks even as cast on the same day . It was explained (by someone from a foundry) as the blocking in the molds for the dipstick tube was differnt and they had just grabbed 2 or 3 of those used on some blocks where others maybe used 1 of them . It is a very similar debate to what you have here w these blocks and around the same time period . M
Interesting coming from a segment of Gm and seeing the same basic debate .

This may help explain why some of the outward differences may have popped up over time with your blocks as well . Rember these differences can be on the same day of casting w the Pontiac block

[70 copo]

Let me start by saying i don't know anything about this topic, nor am I taking sides on the matter...but from what i can tell the images simply show changes to the outward appearances of the blocks over the years, small casting details, etc... How do any of the photos show the actual composition of the iron the blocks were cast from was ever changed? From what I can see, they don't. It would be like posting pics of 67 and 68 camaro fenders and saying because there are outward visible differences, the composition of steel itself must have changed.

Thank you Joe,

Have a look on the 1969 .20 block under and to the left of the cam gallery and leading to the top of the crank gallery. this is a defined bulge with a crease.

Next look at the 1969 .20 block this time at the more pronounced bulge present above the cam gallery to the right and up to the head deck.

Why is that significantly structurally different from the 1973 block with the same casting number?

So the question Joe is; do you think that the differences in the image are just the the composition of steel that has been "changed"?

[cook_dw]

This could just be a situation where an intelligent mind struggles over the simple truth. The flow path of the castings being changed could result in the cure speed which could result in hardness changing due to cool down of the molten iron. Just because the hardness is different from one block to another doesn't mean the composition changed. Take water for instance. You still have 2 parts hydrogen and 1 part oxygen. Different temperatures give you different results in hardness. I really thing you are making this more complicated than it needs to be.

[70 copo]

Darrell,

Post #66 above.

Same question. Care to offer an opinion?

[70 copo]

The flow path of the castings being changed could result in the cure speed which could result in hardness changing due to cool down of the molten iron. Just because the hardness is different from one block to another doesn't mean the composition changed. .

Good. Yes the truth is that some blocks ARE harder than others.

Excellent. I wonder if our expert Bergy would agree with you on the remainder of your informed opinion?

[bergy]

I think I'll leave this discussion with an apology to Phil for offending him. I should not have done that. Maybe we can make "lemonade out of lemons" here. The discussion about nickel and tin alloying is put to bed in my mind, since I actually lived the production and know what the processes were.

The discussion about physical changes in casting profiles might be interesting to the group however - I'll start a new thread and contribute what I can.

[cook_dw]

EDIT: Sorry I would not have replied if I had seen Bruce's post above but his post was done while I was typing mine.

I don't believe anyone was arguing that the hardness of one block vs another was the issue. It was when you (or someone) were correlating hardness changes to composition changes being one in the same. These things do not always go hand in hand. Like Bruce (or whoever it was) mentioned; you would have to do a statistical analysis of a sample from each sample of block. Even then if the mixture time was not evenly mixed you could have higher deposits in one side of a block or even mix to mix or pour to pour. But at the end of the day the same composition is used. My guess is that GM did have quality control for each batch and maybe even throughout each batch if I had to guess.

[70 copo]

I think I'll leave this discussion with an apology to Phil for offending him. I should not have done that. Maybe we can make "lemonade out of lemons" here. The discussion about nickel and tin alloying is put to bed in my mind, since I actually lived the production and know what the processes were.

The discussion about physical changes in casting profiles might be interesting to the group however - I'll start a new thread and contribute what I can.

Thanks.

Please stick around... together we might figure this out.:beers:

[70 copo]

Anyone here track original engine cars that are reported to have the "born with" block as part of a data base?

It would be interesting to see the balance of reported original DZ-302 blocks stated as being original to the car.

It is about 7.5 months of production for both the 618 and then the later 010 so it might be worth a look.

[RALLY]

I had a 69 Block 4 bolt main, 3970010 Casting Number. I was going to use this block to build a 69 Z-28 302 Clone engine. It had the 010-020 cast numbers also with that strengthen 4 cast strips as shown in a picture about this topic. It had the correct 302 Cast Number caps too. It just was not a DZ stamped block. Hope we find out more info about these numbers.

[70 copo]

Think warranty mitigation... and the number of CE blocks GM did not want to continue to pay for...

[iluv69s]

WOWWWW…I posted this question and since have been traveling and just got back to it.

Read through the whole thread. Did not mean to start all this.

Thanks for all the replies.

Without stepping on any toes, To me it’s simple…

Norwood plant manager (posthumous) and superintendent of engine plant chimed in.

Nuff said ��

Thanks SYC . Best site out there. Folks here actually lived it !!