I ended up owning the Dana 70 Mopar made and gave to John Deianna(SP?) that was for his old Duster modified production car, that rascal was really heavy with all the stock brakes on it. It did have a posi in it, not a spool so there is some weight there but there is no way I would do that agian. He got it due to using destroke small C.I. 340 motors that they RPM the crap out of back then, early to mid 1970, he had rear gear ratio from 5.86 to 7.50 that Mopar sent him there are two different ring gear offsets in the stock Dana 70 depending on year and application so be careful on selecting a part number on gears for the housing you get, if you decide to use one