I know of one huge difference. Chrysler changed the rear crankshaft flange in 1962. The 1961 and older big block wedge engines had the crank sticking out more in the back than in later years, and I THINK they used nuts and bolts instead of just bolts back there. Can someone confirm this cut-off year for me? Just guessing, but I bet this changed on Polys, too. mikelj@xxxxxxx wrote: > > Do you guys know if the early 1959-60 383s are B engines and have parts > interchangeability with the '64 383s B engines? ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html.