Hi Dave thanks for your respons

But as far as I can understand the 454 LS7 was supposed to go into the -71 corvette with aluminum heads but that never happend. Maybe that was an all aluminum engine I do not know
The 454 LS7 crate engines on the other hand was a short block and could be bought with either cast or aluminum heads ofcourse dependent on how much the buyer was ready to spend. :-) But I have not realy found out which casting number that was used and what stamped numbers to expect on this kind of engine.

/JR