Block Casting Numbers

[69z2x4]

I am looking for info on a block i have had under my work bench for 25 yrs. It is a 427 4 bolt main with the tall distributor boss. The casting as i can make it out is 3903854. The 3 may be a 5? No pad cods now as it was a race block. Has a K14 cast below # 7 cyl. HP cast every where. Thanks.

[nuch_ss396]

Sherm,

I can't find this block number anywhere. Can you tell me a
little more about it?

Does it have the two dowel pins on the timing cover?
Does it have provisions for the screw on type oil filter,
or the older cannister type?
Where is the casting date located? Is it on the right side
of the block just above the center freeze plug? Or, is it
on the upper rear flange behind the right cylinder head?

In most cases, a tall distributor tower indicates an early
style casting. Late in the 69 model year, the short tower
was phased into production. Although, I have heard that the
'512 block used the tall tower design through the end of
1969 production. Possibly others here can verify that.

Steve

[nuch_ss396]

BTW, the only '854 block I can find is the 3969854, which was
the first 402 block used in late '69 production. However,
that block was reported to incorporate the "new" short
distributor tower design. http://www.yenko.net/ubbthreads/images/graemlins/hmmm.gif

For reference, the '854 block I have here uses the short tower design.

Steve

[69z2x4]

New info on block! Talked to someone who refreshed my memory on this block.
In the late 60s and early 70s the NHRA required you to run the same year block as the car in SS and stock. When these camaros were new the blocks were not that easy to find. This blocks numbers were changed to fit the class they were running at the time. The numbers on the block now are 3969854. I know the 9 and the 6 has been changed. The three i an not sure about. The casting num on the side of the block below the freeze plug is J 10 8 It has a screw on oil filter. Also has the extra plug at the oil filter for external oiling. I still would like to know what this block was born in. Thanks for your input.

[3macs1]

There was a 454 block 3969854 2 or 4 bolt in addition to the 3969854 402. I may be off on the years but I think 70-91. http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif

[69z2x4]

Tall Distributor boss, 396?85? 4 bolt main, casting # J 10 8

[3macs1]

No I don't think that 454 would have a tall boss. It is not a tall truck block by any chance. Not all of them had truck stamped. They were 3969852 for the 366 and 3969858 for the 427 from 68-85. cannot see it if you raced it but just to eliminate another possibility. Easiest way to tell is how much material is there between the top of the water pump bolt hole and the top of the deck. Truck block cannot be missed when you look there.

[nuch_ss396]

The 3969854 block was a 402. GM would not use the same
casting number on different c.i. displacements.

The J-10-8 however is way too early for an '854 block
as they came into production late in summer of 1969.

Check that casting date again.

Steve

[3macs1]

Chevelle boys and other lists state differently Steve. 854 was also a 454.
http://www.yenko.net/ubbthreads/images/graemlins/hmmm.gif
http://www.chevellepages.com/numbers/BigBlock-Casting_Numbers.htm
http://nastyz28.com/sbchevy/bbparts1.html

[nuch_ss396]

Joe,

I followed the link - but I don't believe it. I've never
seen an '854 used in a 454 application. Colvins books don't
even mention the '854 as a 454 and most consider these the bible.

I'll look into it some more and get back to you. Got my
curiousity peaked http://www.yenko.net/ubbthreads/images/graemlins/hmmm.gif

Steve

[69z2x4]

The casting date could have been changed also. I am sure the 8 in the J-10-8 is right. The 10 looks suspect. Thanks for all the replies.
Sherm

[3macs1]

Hi Steve:
We are going to have to rewrite that book I think for them. http://www.yenko.net/ubbthreads/images/graemlins/wink.gif
See I am still 100% convinced they made a 4 bolt 512 oval port since I sold one undrilled for oil cooler and seen two pictures of others since. The Judge may say no but I know now what I had. http://www.yenko.net/ubbthreads/images/graemlins/rolleyes.gif With this 854 block the first link would not suprise me to be wrong but not the nastyz one or I have found at least three other lists the same.I still have some 402 and early 454 blocks that are not 512 but they are buried.
I will see what else I can locate also and between us we will figure this one out. take care http://www.yenko.net/ubbthreads/images/graemlins/beers.gif
Joe

[nuch_ss396]

Joe,

I would love to meet anyone ( still around ) that worked at the
Tonawanda facility one machining operations for the big
blocks. I've got tons of questions I'd like to get answers
to. Anyone know if any of these guys are still around?

I could imagine a block being drilled & tapped for 4-bolt
mains if someone just goofed. Can't imagine it would hurt
anything. But I'm positive that all the SHP blocks, which
were 4-bolt mains, were also drilled for the external oil
cooling provision.

I'd be shocked if an original SHP engine was found with
4-bolt mains and no external oil cooling provision.

Steve

[3macs1]

Would be nice to talk to someone agree. I just know I had one out of a big 70 impala of all things and there was pictures of two more posted on this site after.I thought I sent them to you. One was a marine engine but the other was not.

[69z2x4]

STEVE; Have you ever talked to any one that worked in a GM plant back in the day? My brother-in-law worked in the Norwood Plant in 1969 and most likely assemdled some of the cars we talk about here. He was a Marine in NAM in 67. He does not want to talk about that either.

[TC]

Pretty interesting stuff.

[nuch_ss396]

[ QUOTE ]
STEVE; Have you ever talked to any one that worked in a GM plant back in the day? My brother-in-law worked in the Norwood Plant in 1969 and most likely assemdled some of the cars we talk about here. He was a Marine in NAM in 67. He does not want to talk about that either.

[/ QUOTE ]

Sherm,

No, I haven't. But like I wrote earlier in this thread,
I'd love the opportunity to dig a lot deeper into this
subject. http://www.yenko.net/ubbthreads/images/graemlins/laugh.gif

[69z2x4]

Thanks for all the input guys. I don't know if i will ever figure this one out. 396?85? date??8 4 bolt main, tall dist boss. Sherm

[3macs1]

Any chance of posting a few pictures of the dates etc???