I acquired a 1970 Cutlass Supreme and know very little about its history. I am about 90% sure the engine that was in it was the original. The VIN from the car shows it was the 14th unit (100014) out of the Framingham Plant. I am at the point I need to decide to put alot of work into trying to restore/rebuild the engine or find a suitable alternative. The strange thing is that it does not have any markings on the pad where it should. Unless it is so far gone that I just can't make it out. One of the bores I measured comes out to the original size, 4.057 in or 103mm, so I know it hasn't been bored.

Here is a picture of the stamp pad. Any suggestions for further determining if its the original engine?

Thanks.

 

The heads on a 1970 350 should have a #6 cast on the left side of the head.

 

Thank you. My heads are #6 so I know it's a 1970. Are there any other VIN markings on the engine that I can look for? Or do the numbers on the oil fill tube identify anything? My Julian date on the back of the block is 140 so that would be May. Can I infer anything from that date? Again. Just trying to determine if the car has the original drive train. Where would the VIN derivative be located on the TH350?

 

The only VIN stamping on the engine would be on the pad adjacent #1 cylinder which, in your supplied image, appears to be blank. Unfortunately so, because once that's gone there's no way to determine that the engine is original to the car. However, somebody with better casting number and date code chops than me may be able to rule the engine's "born with" status in or out. But it'll never be "matching numbers". The heads could have been swapped at any time in the last 55 years, so the fact of their being #6 is really no guarantee of anything.

The transmission should also have a VIN derivative on the driver's side pan rail, so you may at least be able to confirm its originality.

 

A. On what are you basing your 90% sure its the original engine block ?
B. If your Cutlass was the 14th out of Framingham, it was likely produced in July or August 1969.
C. What alternative are you referring to ?
D. Engine pad looks to have been ground with a disc sander or grinder. If a flat sharpening stone doesn't shine the whole surface, you just proved the engine ID was ground off. Without the first two digits present, you can't even prove what year the block is.

E. There has been a 140 Julian date every year.

 

Thanks. The place I bought the car from stated the car was junked, for an unknown reason, in the 90s by an older couple who were supposed to have been the original owners. I did find a broken exhaust valve on number 7. Everything else on the car appears original. Based on what I see, I have no reason not to believe the seller. Just checked the trans and it has my VIN derivative. Alternative would be a different engine, whatever I would decide to get. But I would prefer to keep the originality of the car if possible. I see no reason why someone would have obliterated the pad numbers. Especially if the numbers were still on the trans.

 

Agree, there's no reason to grind the number off the engine unless it was stolen or something but the fact remains that it ain't there. Fortunately, originality is no big deal in your case and the status of your engine shouldn't keep you from doing whatever you want with it, whether that's building it any way you want or replacing it altogether.

 

The stamp on the oil fill tube is the engine unit number.
The first digit of the engine unit number is the model year. The rest is just a sequential engine build number.
Oil fill tubes can be swapped so its not a definitive marker but odds are the one on yours is probably original.

 

Thank you, I stand corrected.