like Dave's post above Mike, while my 'cuda isn't a hemi, my #'s match 440 was cast 07/31/69, top pad stamp is G 440 1 8 HP - and the G is stamped over a faint F, and my 'cuda is a 1B4xxxxx vin built 05/26/71 - when I spoke to GG about this, he told me the same as was mentioned above, they just grabbed whatever was available to get them off the line, nobody thinking about 40 years later and casting dates - I'd think could be more norm with a hemi due the less amount to choose from as Chrysler was winding down production of HP stuff and there was less to choose from - at least from the hemi blocks?