Does any one know what the numbers are in this stamping on warranty block CE262603 are they some kind of date code?

The Corvette Black Book lists for the block code 396512: 454ci, 365hp, 425hp

I didn't see anything mentioned about warranty blocks.

What are your numbers.  Casting date should be just aft of the passenger side head down on the block by the bell housing.

Was there supposed to be a picture in your post?

Casting number is 3963512

Judging manual says that is a 70 or 71 big block.  What about the casting date?  Should be a letter and 3 numbers down by the bell housing mount just aft of the right head.

delete

Here ya go, read this.

http://chevellestuff.net/qd/engine_stamp_numbers.htm

Good information. Hope it will satisfy the user and answer all questions. 

That's interesting stuff - not something I knew much about!🙄  Thanks!