1970 Camaro Z/28 engine numbers - help?

[Dave Castine]

Guys - I went to see a very nice 70 Z/28 yesterday that is coming up for sale, I need help to decode the engine block. The top end of the engine is original to the car but the short block was swapped out years ago... Can anyone help me? Many Thanks!

[BCreekDave]

Love them green 70 Camaro’s
I’m far from an expert, but looks like a restamp
The flash flare doesn’t help. Is that a CRI or CRT?
Is it a 4 speed or auto?
You may already know, but Z’s had black grilles but the grey looks good.

[seventieshow]

Lots of people on here that know a lot more then I do, but that is an odd looking stamp. Check the bell housing flange for a casting date and 3970010 (or whatever it has), that will also help.

Nice looking car.

[big gear head]

Looks like it was stamped at a machine shop after decking. RHM might be the machine shop that did the work.

[ZLP955]

Fainter second row on the left seems to be a partial VIN, and I see what looks like part of an assembly stamp/application code over on the right. The rest of the stamped letters/numbers look to be added, could be by a race engine builder or maybe a machine shop, as already suggested.

[ronzz572]

The original block would have a VO stamped and then the assembly date then CTB for standard shift motor. Or CTC if a automatic. Example V0626CTB. The partial vin can be stamped 2 different places depending on if it's from vannuys California or Norwood Ohio. Norwood stamped on rough cast side of bellhousing near oil filter. Vannuys on the front pad and rough cast area. Your block surely appears to be a decked replacement 350 block. Stamped by the rebuild possibly. Also if your vin matches the legible partial vin and block cast date is in line with the Trim tag date it could be the the original. Better pictures of the block pad stamp, cast number, the cast date partial vin may help take this further. If you can post some better photos of the block stamp that can help?

[Dave Castine]

The car is three hours from me, but I'll forward your comments on to the owner and see if he can get me more info - thank you everyone (especially RONZZ!)

[lbnaz]

Do you have photos of the engine compartment. Looks like my old car and it wasn't stamped then it had a 69 350 block built like an LT-1. Did this car sell at BJ couple years ago in Vegas.

[RichSchmidt]

Get the casting number and date off the back of the engine and it will at least put you in the correct time frame for looking up the codes on the front. GM reused almost every code over the years so you could have any engine from the late 60''s thru the mid 80's.

[RichSchmidt]

If it did happen to be an engine code CRF is a 1975 350 2 or 4 bolt. There is no letter that looks like an upside down V so I would say that it could have been stamped at GM with the letter V installed upside down.

[Dave Castine]

OKAY - got the story, talked to the previous owner who had the car for 20 years before the current owner of 10 years bought it (Uncle sold to nephew). The engine was rebuilt but he swears it's the original block. The numbers on the block are attached on the pics, the block is stamped as a correct for '70 on the back by the bell housing with 3970010. It also has the 12-bolt (70 only), 8k tach, LCA blocks on the bumpers, and being a NORWOOD car it has the Z28 called out on the cowl tag.

[BCreekDave]

The 3970010 actually doesn't mean very much. That was a block they used in both 2 bolt and 4 bolt configurations from 1969 through I think the early 80's in both cars and trucks. There were probably more small blocks with this casting number than any other.
The ACRE 10232 is pretty much meaningless in terms of factory stamps as far as I know. Probably an engine shop stamp. The cut marks on the pad are definitely wrong too. The factory broached the head surfaces on the block and the marks left from the broaching process look totally different.

There is a casting date code at the rear of the block on drivers side top near the bellhousing. It will be of the form LETTER-THREEDIGITS where the letter is the month and the next 2 digits are the day of the month and the last digit is the year. Post those and we can at least decipher the time when the block was cast. The casting date should precede the cars TT build date by as little a 1 to as much as 4 or 5 weeks generally. As an example, my car has a 04B TT date and the block was cast C230 or March 23rd, 1970.

There is VIN number stamped near the oil filter on the block by the bellhousing. It is very hard to see as its on the rough casting, especially while its in the car. This would be the gold standard to tell if the engine is original to the car. I had to photograph mine from various angles with both a flash and no flash with my iPhone to make out the letters. You may need to take some lacquer thinner to remove the paint. Don't use a wire brush!

Still sounds like a nice car. Can you post more photos? The TT indicates a deluxe black comfortweave (712) interior.

[Kurt S]

You can guess all you want.
Or you can get a good picture of the engine pad without paint and know......

[Jonesy]

I agree a clean pad will help. What I initially see is possible rebuilders stampings. Head markings look like 186 heads.

[YENKO DEUCE REGISTRY]

Are the LCA blocks under the bumpers a Z28 only thing?

[Ricks72Z28]

Yes, they are a Z28 only, due to the fact they had15 inch tires.

[Dave Castine]

A few more pics

[x77-69z28]

Small observation, but knowledge is good. The 70 dash does not have the seat belt warning light. That, and the valve covers are on the wrong sides.
Buddy

[Mr70]

Dash mounted Fasten seat belt light was on the 1972-1981 Camaro.

[Dave Castine]

I knew about the dash (noticed that today), didn't know about the valve covers - thanks! Love learning new stuff - it keeps me honest!

[Charley Lillard]

On a Z28 the gas pedal attaches to the floor instead of hanging from above.