Ok why do I need a upper arm? These are designed for the 4″ drop and to work with the Calmax lowering arms CA3097L-4 and 2" coil springs CS3097-2. Their job is to set the upper ball joint at the correct angle when lowered, and set the proper length in cooperation with the lower arms establishing the correct camber and caster angles (good alignment & tire wear). They work great with bags and have all the cool stuff the lower arms come with (urethane bushing, ball joints, etc). That’s Calmax, that’s DJM!