Hi everyone,

Im posting this for a friend of mine who doesnt have a computer. hopefully, I will be able to get all the info you need. His question is this- He bought a 1970 Chevelle with the SS 396 motor. We just pulled the alternator off to replace it and decided to write down the numbers that were stamped into the block. When he bought the car, the guy told him that the motor was a warranty replacement block. Might one of you know how to decode the stamped numbers in the block to verify if this is indeed a warranty block? Thanks, numbers stamped in are as follows:

(left to right)

00I6T0408CTW

(the 6 was very lightly stamped into the block with the stamping being deeper on the right side of the nubmer so it might be some other number, but from what I could try and tell I think it is a 6.)

Any help with this would be greatly appreciated so we can verify that this is a correct motor for the car or a replacement warranty block.

Thanks again,

Brian

In the GM paperwork I have for decoding engine ID codes, it says that the engine code is the last symbols of the ID number, in your case CTW. CTW denotes a 1970 396(402 CI) 350 HP motor used in 1970 Camaro, Chevelle, or Nova. CTW also denotes a 400, 175 HP used in 1976 Chevrolets. I can't tell you what the other numbers denote.