The 55-57 rear end is what I call a bolt in.The brake hose will even hook up.I used 55-57 shock mounts and lowering blocks from (Brockmans)and they had the offset holes.Ask for 57 ubolts. I like the 57 rear end better because it has a drain plug.I was able to splice the hand brake cables to the 50 stuff too. SCRAP