SBC indetification help

[mb911]

Hi everyone,

I bought a 67 camaro in August and am doing a complete rusteration and while I am in there I am trying to figure out what engine I have. it is a Small block casting number 3970010 and I have verified it it is a 4 bolt main with what looks like a factory windage tray. on the front pad it has what looks like 15565686 stamped into it and thats all. in the back by the 3970010 number ther is a GM35 cast in there . I do know they heads are the very undesirable 624 heads. I am going to try to figure out the front pad better but thats best I can tell

 

[ChevyHiPro]

Welcome to the forum and thanks for posting!

Engine Casting Number - 3970010 - this is a very common block casting number, cast from 1969 to 1979, in 1969 it was made into 302 and 350, from 1970 on, it was made only in to a 350, both 2 & 4 bolt mains, 4 bolt most common, used in cars & trucks.

The front pad number you've posted, 15565686, doesn't fit any of the normal sequences for these numbers.
I'm assuming the front pad is located on the passengers side, just under the head.
Normally there are two numbers hand stamped on there.
The Engine Partial VIN, it would look like this - 13N132794
The Engine Assembly Code, it would look like this - V0112CLJ
The code numbers are hand stamped and can be lightly stamped and hard to see.
Also, they can be obscured by paint, dirt and grease.
Usually, a through cleaning with solvent, a wire brush and a rag will display the full numbers, unless it had been damaged by previous work.

If you'll check the passenger front pad again, possibly clean it a little, you may be able to get the full numbers.
Please post them and we'll try to get more info on your engine.

 

[mb911]

Ok just looked again scraped/wire brushed etc same numbers show up no letter designation. the front boss is a different shape then what has been posted jn previous threads. I wish I still had the pan off I could have found numbers on the crank that would have helped? It does also appear to have stock windage tray and I am not sure what application it would have been?

 

[ChevyHiPro]

Sorry to have put you through that scraping and brushing to find the same numbers!


I'm going to venture an educated guess on this engine.
Here's some facts to somewhat justify this guess.
In 1970, the federal government issued regulations to begin in 1972 model year, requiring all engines, frames and transmissions to be stamped with a partial VIN number for vehicle theft identification.
Sometime in the early 1971 model production year, GM voluntarily began their Engine Partial VIN Number and Engine Assembly Code Number stamping on assembly of an engine into a vehicle, and in the process, standardized the stamping location and number format, as mentioned and displayed in the above message.
This numbering format was formally in place and standardized in all GM assembly plants by the beginning of the 1972 production year.

So, now what about your engine?
Here's my guess;
From your detective work with the pan off and the discovery it's a 4 bolt main, and the unusual stamping sequence on the passenger front pad, I think this is a 1969 - 1970, 4 bolt main 350 cid engine.
The 302 cid engine that was made from this block casting in 1969 (only) was 2 bolt main, the 1969 - 1979 350 cid was 2 & 4 bolt main, 4 bolt being most common.
Without a decodeable Engine Assembly Code, it's going to be tough to figure out what was the original engine configuration, horsepower and vehicle it was installed in.
If in fact the windage tray is GM, it is possible this engine came out of the factory in your Camaro.
The addition of a windage tray was used on high performance engines/vehicles.
It's also possible the windage tray is from a later model engine and added by a previous owner.
The vintage of the engine and the Camaro are very similar.
But, this many years later and several or many owners later, it is going to be hard to tell!
Another 'test', would be if you ever have the heads off, measure the bore, a stock 350 is 4.001", that'll take a dial caliper or ID micrometer to check.
At this point in time, it's a safe guess the engine may have been bored as well, +0.020", 0.040", 0.060" are the common overbore sizes.

I hope some of this information helps!
Good luck with your build and don't be a stranger on the forum.
Stop in from time to time and tell us what's happening with your project!

 

[mb911]

Awesome thanks for the help. I can tell you when I had the Pan off on the gasket mating surface the cylinder numbers were stamped into the block which I thought to be strange. the rods also have a series of center punch indents I assume to identify location. It has almost definatly been rebuilt at one time for sure. There was a ton of RTV on it. There are some of the parts like the balancer that were painted GM blue but I suppose some parts may have been mixed and matched over the years. it even had an aluminum early 80's GM intake on it so who knows.

 

[ChevyHiPro]

As you say, this engine has been rebuilt, at least once.
With an engine that old it would be a miracle if it hadn't been rebuilt!
So, just take it for what it is and built it into what you want!

Good luck with your build and don't be a stranger on the forum!

Stop in once in a while and post an update on your build!