These arms eliminate upper ball joints w/ super strong 1'' ID Stainless American Uniballs. Additional caster is built into Arms for greater align ability to help with problematic leveling kit alignments. Allows for increased wheel travel using front 2.5 Dirt Logic Stainless Steel coil over shocks and rear 2.25 Dirt Logic Stainless Steel shocks. Chromoly tubing reduces flex found in stock arms for more positive road feel. 4340 Heat treated Uniball pin fits into factory ball joint taper without modification to the spindle for easy return to stock feature. Arms are direct replacements for factory arms on suspensions that require additional strength and align ability. Material Construction Specs. Built with same materials as found on Trophy Trucks. .120'' Wall 4130 Chromoly Tubing. 1.25'' OD. .250'' wall DOM Bushing Barrels. 1'' ID Stainless Steel American Uniball. 17-4 Stainless Misalignments. Heat Treated 4340 Tapered Uniball Pins