Measure the trans angle with a angle finder first. should be between -2 and 0 deg. adjust your pinion angle from there. (with a 4 link i believe -2 is what your after because it doesn't move as much as ss springs) if the trans is pointing down towards the rear -2 than the pinion should be at 0. if the trans is at 0 the pinion should point down -2. I may be wrong but I read up on this topic for a solid month.
