well i put the stock top end of my motor for sale on CL. and someone was interested in the heads but wanted the casting numbers just to make sure. when i told him the casting number he replied saying that they were 79 heads not 69. so i checked and he is right. then i decided to check the casting number on the block and found out that the block is a 74 block. very strange. i wonder why someone pulled the 69 out and swapped in a peiced togther 70s motor. the internals look amazing on the motor and if it wasnt for 2 of the freeze plugs having big ass holes in them i would think the 69 blew up and they replaced it with the 74 with a fresh rebuild or something.