I have used Dr. Diff's 35 spline axles in my D60 now for 5-6 years. 3740lbs, Trans Brake, Radials, 1.37 60ft behind the turbo small block.

It ate a stock planetary, and rear sprag in the trans (with Low Band Apply!), but never hurt an axle.

It did bend the 1/2" wheel studs, so I upgraded to 5/8".