Hy guys, I really don't want to appear picky here, but if we're going to talk wheels, lets be specific. As Spanky said the six bolt pattern has been used by GM for years, the early six bolt wheels were Motor wheels, not Budd wheels. Motor wheels are hub piloted, Budds are stud piloted, and they use an inner and outer nut system for dual wheel retention, while Motor wheels use only one nut with a swiveling washer in all wheel positions. My Canadian parts books say that 56B was the first year/portion that six bolt Budds were offered on Chevy trucks. 56B was also the first year/portion that tubeless tires were offered on Chevy trucks, at least in Canada, hope that helps.
