Crew C30 vs C20 differences

[jetmech85]

I have an '85 C-20 crew with 14 bolt full floater. I can provide specific measurements for you if that will help. I also have an '82 C-30 crew cab dually that is picked clean but still has the rear end and springs to compare. As far as the front I can't confirm but I believe you are correct, just install single wheel hub/rotor assy. Some C-30's used air bags inside the coils and the lower controll arms are different (heavy duty) on those. Noticable mainly in the pivot shaft (eliminates the "U" bolts) and bushing area.