The 1/2 ton axle and the 3/4 ton axle are the same measurments in every way but the king pin dia. 1/2 ton kin pins are .866 dia 3/4 ton are .920 dia. The 1/2 ton will bolt right in the 3/4 ton. You can even use the 3/4 ton steering arms. I've also addaped 1/2 ton spindles to a 3/4 ton axle by boring out the 1/2 to spindles and using 3/4 ton king pins.
