hello, i am in the process of buying a 1978 chevy g10 cargo van , it has a chevy 406 small block engine and a dana 60 rear end ,it is a drag racer, and since i dont want it for racign  i would like to change the engine transmission and rear end, i would like Some muscle in the engine, just to cruise around , but i do not know what kind of rear end to get  what kind should i get ?