Best bet on rear suspension?

hi, the dana 60 from a 1967-1972 1/2 ton ford pickup is the best one. it will weigh 32 #more over a 8 3/4. It has passenger car ends and has 3" dia tubes.
as for slowing you down? not an issue!! I went with a dana 60 in my 340 duster in 1992. didn't loose any E.T or MPH. the car ran excatly the same!!
the car runs 11.40's with a 4 speed trans. as for using calverts and S/S springs? don't!! they will bind and bend housings. use calverts system, it really works great! also, use a synthetic lube in rear and trans. it will improve the life of them. calverts has springs, bars ,shocks. matched setup.