I just purchased a castiron V8 powerglide and was told it was from a 1956 car. Is there a way to confirm this. I read where there should be a serial number stamped in the lower right hand side of the case but I can't find one. I believe the 1956 is different internally (clutchplates)from the '55 and '57.
Thanks tom

The ID number is stamped into the right rear corner of the case, facing to the rear, between the bolts that hold the extension to the case. Between the right lower bolt and right side bolt but on the PG case, not the ext. True, the clutch assembly was different + had a few other minor tweeks.

Thank you. it looks like C1122N.

I believe this means Cleveland powerglide/Nov. 11th/night shift. I guess it will have to came down to actually see what year it is. It has to be rebuilt anyways.

The last diget should be a number for the year. 5 for a 1955, etc. There may also be a date code on the side of the case behind the casting number.