BED needs to be 5 1/2 inches off frame. I used c channel I had made so same width as frame.I fit 2 frame rails each end to bed,set bed on and centered over wheels.marked and drilled end rails.back off with bed to drill.measure between end rails.add 2 rails between end rails.decide how you want to mount.common sense,easy.If your trucks same as mine
your gonna cut 13''s off back of frame on truck,that way bumper can go on.then you take second bed cut 2ft off frnt , box in and mount in gap
If you need more info PM me Ill give my # well talk on phone.To hard to explain here henpeckin,easier on phone. John
Man that red truck is bad a$$,love the suspension