In the back of my garage, holding a tape measure close- they're within 1/4"... The case seems to be the same... If your interest is deeper than that, I could pick up some of my old greasy parts and give a better answer... Karl
I think the generators are the same length. However the 8BA generator is farther forward on the engine. The fan belts were moved forward in '49 to make room for the post distributor.