Fat Man is a full service chassis shop. They are best known for their Mustang II front suspensions. They fabricate crossmembers for a wide range of vehicles and offer their own line of Mustang II based suspension components. They also offer rear suspension kits (springs, shocks, etc.) for some vehicles including First Series pickups. I am sure they could get you a new rear end if that is what you want. They can also give you some good ideas as to what to look for if you decide to sourse one from a yard. Fat Man advertises in most of the hot rod and truck building magazines.