From 1966-1972, Broncos came with manual steering. From 73-77, power steering was optional. The power steering boxes from 73-75 turned approximately 6 turns lock-to-lock and from 76-77, 4 turns lock-to-lock. Some people prefer the 76-77 box because of the quicker turning ration. Others prefer the earlier box for rock crawling because they're easier to turn.