I think I found the right numbers. There are two of them close together. Both look as if they were stamped in a piece of metal, and then screwed to the mold. The first one is: Screw head CON3 Screw head: The next one is Screw Head, H2ll Screw head. The second one would seem to mean the motor was built August 21, 1961. Do you agree? What does the first number mean? There is also an another number further down the block. #3769716. What is that? I thought that was the casting number,and it indicated the motor was built between 1959 and 1962. On the other side of the motor is a Casting mark that says GM with the number 15 under it. Does that have any meaning. All this is confusing to me. Thanks for your help. Allen
