[OrrieG]

Ray is right, some guys in the 60's ran 3/4 ton truck rear ends with 4:56 ratios too. Others ran Old's which if I remember right had larger ring gear bolts. Those old Chevy rear ends will take alot of abuse, I field tested them in 55, 57, 60 and 63 Chevys! Weak link were the universal joints, especially the center carrier in the 63. Never blew a rearend but carried spare universal joints and tools to replace them all the time.