When welding new spring hangers on an axle, (Leaf spring SAS) what angle should you have the pinion at? Lets say you're shooting for 6" of lift.
Shouldn't you focus on caster, and go from there?
Well, for starters, you cant change them. The perch on the driver side is cast into the diff, so youre stuck with Ford's angles. You could shim the springs like you would do for the rear axle to correct for pinion angle, but i dont recommend it since like Ralphenstein suggests caster angle is MUCH more important than pinion angle. Set the caster to spec & whatever the pinion angle ends up is what its gonna be. For a 6" lift the stock angles will be fine.