i just read in that there is TWO 383 motors. a B block and RB block. when was the RB 383 made? it has a 4.030 bore and3.750 stroke compared to the B 383 with a 4.250 bore and 3.380 stroke. weird. and yes the 400 4 barrels had "better" cranks. i only have 2 4 barrel cranks or else i would...