This one is a little tricky. GM's assembly plants generally shut down for the month of September to retool for the new models. So they were building cars and trucks through August. The lead times for the motors were usually a couple of weeks, not several, a couple, like may two or three at most. But we are at the end of the production line for one year and the beginning of another. Did GM start building motors for the 54 line a little earlier then usual just at the beginning? Maybe. I have an 848 head in my garage that was cast the second week of September of 55. The 848 head was introduced for the 56 model year. We know, no cars or trucks were built on the 55 line after July 30 or so. So between the casting date and the 848 head, is a 56.
As for your block, I don't think anyone can say with definitive authority that every single block was stamped on the distributor pad. That was indeed the practice up through at least 55, but can any say for absolute certain? I am not sure that they can.
So, Joe, can you post the casting date of the head and the block? Lets see what we have here.
Last edited by Dragsix; 03/05/2024 5:44 PM.
