56 GMC with nova clip, air ride question.

[BIGglaSS]

My plan is to run 20" Detroit steel wheels with 5" backspace, 245/35/20 rubber, dropped spindles and to get a little more room, 1" narrowed tubular control arms.

Truck looks nice! What width wheel? 5" backspace and 245's with stock control arms is a tight fit when riding low. 1" shorter will definitely help. Your plan should work. You may have to roll the inner fender lips to get it to turn more when low.