My Randy's Ring and Pinion book says that the Ford 9 inch 35 spline axle shaft is 1.5" in diameter. For the Dana, I'm assuming you mean the D60. The only diameter reference I can find for 35 spline D60 parts is for my 35 spline stub shaft upgrade and those are 1.5" too. I see that there are diffs and lockers for D60 rear ends that are 35 spline, and there are axle shafts for those, but the diameter isn't specified here. My rear end is a D70U with 32 splines and a 1.75" diameter axle shaft, so obviously its possible for Dana-compatible parts to vary in either diameter or spline count independently.