TheSaint

I am trying to find out what the cast number for 1970-72 Corvette LT-1 engines

I found one car with a 3970010 engine block that said it was a LT-1 engine

Is this correct?

Easy Mike

Almost certainly. 010 blocks are widely used generic 350s and applicable to LT-1s. Check the remaining numbers.

Mike Ward

The 3970010 block was cast in the millions by GM at all three engine plants over a 10+ year period and used in virtually every car, truck, industrial and marine application during that period.

Obviously only a minute % ended up as LT-1 engines.

As always, all engines that have become separated from their original cars 'came from a Corvette'.

TheSaint

My point is that i was sure that the 1970-72 LT-1 engines would have a number that was only for the LT-1 engine blocks
But from what i can tell it does not look like that


I have a 3970010 engine block and i know that this block came from a truck so there is nothing new for me about the fact that the 3970010 block was used on a lot of different cars

Mike Ward

You asked for the casting number. Both of us confirmed that it is 3970010 .

??????

If you were asking what stamp pad codes were used for LT-1, that's very different. Each engine spec had a unique code- but you already know that from your C2 experience.

TheSaint

I just thought that the 1970-72 had a casting number that only was on the 1970-72 LT-1 engines.

What is the most easy way to stell that it is an LT-1 engine block?

Mike Ward

You can't. They're no different than any other 3970010.

2000HdTp

There is also the 3970014 casting number that was used in LT1's.

Mike Ward

Possibly a few very late '72s but again this alternate casting number was not unique to LT-1 or Corvettes.

2000HdTp

I agree. I have read that it would be late 72 as well. My 72 LT1 in the high 16K VIN range has the 3970014 block with a March 2nd casting date.

LeMans Pete

Suffix code.

http://www.corvettecenterusa.com/Cor...ne%20Codes.pdf

7T1vette

The differences in the LT-1 engine and the other Chevy small block engines were the internal and external parts assembled to those [identical] engine blocks. There were some machining differences also...for Corvette-only features; but the block CASTINGS were the same.

62corvette

If it has two-bolt main caps, it is not an LT-1.

Mike Ward

Care to elaborate?

7T1vette

Threaded holes for mounting the plug wire shielding, for example...

Mike Ward

Non- Corvette engines also had threaded holes.

Carl 72

motorbooks corvette restoration guide says march was the first month for 014

2000HdTp

Did they give an indication of how many were put in corvettes? I have heard that they are fairly scarce.

kenba

010 Truck blocks also had 4 bolt mains. As others have said there is no way to tell a LT-1 cylinder case from any other that has been drilled for a 4 bolt.

TheSaint

I suppose this answers my question very well

Thanks for clearing this up for me