The stock axle will work just fine ( 300mph dragsters use a straight axle) IF you rebuild it to like new specs. A big mistake is while shackles are nearly always attended to the rear spring eye bushings are not and this lets the entire axle move about. New king pins, shackles and bushings, and all rod ends will do the trick. With the power steering you want the caster can be increased which assures a straight line no drift drive. We have used a lot of 4wd Toyota p/s units but I believe the electric p/s set ups sound just as good. Will do one at first chance. Had a 56 come in with a true 28,000 miles on it where a horse had BITTEN the hood and wanted us to repair and paint match the spot. I know it's hard for many to believe but these trucks drove good and the 3sp shifter actually worked good when they were (nearly) new.
