I'm going to call CPP and see what they say about adding dropped leaf springs in conjunction with the drop axle. I think I'm going to go ahead and change out the springs regardless. Here is the proximity of the MC to the exhaust. It may be fine, not sure. I'll have to wait until I have everything hooked back up. Man.... this thing is gutted. No wires, no brake lines, no motor, no trans, no axle.... I hope I can remember how to put it all back together. Next in line is to get the holes in the firewall filled and the doghouse painted. I ordered one of the hole punchers from harbor freight. Gonna hold my plug in place with a magnet on the backside long enough to tack it and then finish it up. I'm developing a strange bond with this truck.