Outer Limits 4x4 Board

Installed a 3" lift and superior drop boxes the other day in a 98 GU lwb, since then under heavy braking I'm getting a rotating grinding noise from what I think is the front right and or left. It only really occurs under quite heavy braking, 90% of the time it won't happen. Double checked all the bushes, everything is tight and good, new panhard rods...No scrape marks on rims or calipers... Could it be something with the brake rotors? The pads have plenty of meat on them, and the sound wasn't there before I installed the lift...

Any ideas?

have u bent one of the dust shields against the rotor? also check you tail shaft on the crossmember