But you can come close by checking the casting dates on the block, head, tranny case, rear axle gear housing, and several other items. I.E. if the serial number of the truck shows a build date of April, everything should have a casting date of approximately Feb. or March. My 51's serial # shows a build date of March and remarkably all the castings had a date within a few days of each other. The blocks date was March 6 and the head was March 7. Chevy must have been pretty busy as they didn't let those castings "season" very long.
Bob
