i bought a set of 4" springs along with 5.5" schackles. the springs don't have wedges built into them to help correct the pinion angle. it includes a left side shim which i guess is used for clearing the drag link, right? what's the best way to get my pinion back down? should i cut off the factory spring mounts and relocate them?

 

You have to cut the spring perches and shock mounts off the axle and rotate the pinion up. then tack every thing Be sure to double check the pinion angle before welding every thing up. Tom Woods Driveshafts can send you a little card that you can use with a string and a plum bob to set your pinion angle. They diddent charge me any thing to send me one. Also dont heat the axle housing up to much it could become brittle in that spot and have an increased chance of breaking or bendin, just take your time with it.

 

Do that more than a degree or two and you'll screw up your caster, which creates steering problems. That's why you have to cut and rotate the knuckles also if you do what's suggested above. Caster is more important than pinion angle.
The 4" lift springs start the problem and the longer shackles compound it. Try it with the stock shackles before doing anything drastic.
Or you could buy some shims (what you refer to as wedges) to correct the problem.

 

The shim is for the drivers side because the spring perch on the pass side is built higher and most aftermarket springs don't compensate for that.