Ok, so as long as the engine is a 1967 or older, there should be no problems with it bolting up to a 65 B-body auto tranny? Going back to my original question .
64-67 small register vs 68 & up large register.
Obviously large crank register will fit both and you can buy a bushing for the early convertor nose to larger register...or have early guts put into a later convertor case .