a body rear end ? 8 3/4 vs dana 60

exactly and when you get the dana cut to the CORRECT dimension for your A-body (narrower than stock) the weight is barely any different.
Jim Hale told me he lost weight when he changed to a dana 60 >w/ a caltrac system, because of the diff. weight of them and the superstock springs. That was on 67 barracuda nhra stocker.