Greasable 88-98 IFS Rear Spring and Shackle Bushing Kit - Kevlar
Fourwheeler Magazine's Project "Stinky" gained 50 points on the test ramp and about 1 ½" of rear shock travel just by replacing the shackle bushings. These work! Drilled and crossdrilled grade 8 bolts and sleeves and channeled bushings allow you to lube your poly bushings for better ride, less wear and eliminate bushing "squeak".
A often misunderstood fact is that factory rubber bushings offer less flexibility than aftermarket urethane. Most people have heard or read otherwise but rubber does not work as well in the real world. The reason is that the factory rubber bonds the inner sleeve to the outer sleeve and spring. Since they're bonded together, the inner sleeve can't twist relative to the spring. When you tighten your shackle and spring bolts the inner sleeve is locked solid to the vehicle so the suspension is limited by the rubbers inability to rotate. Urethane bushings on the other hand, can rotate freely around the inner sleeve and will not bind up the suspension.