My mistake may be your great find .. I bought this Service body thinking it would fit on my Duramax (WRONG) ..
Regardless, I had some minor metal work done to it and had it painted (to match my truck of course) .. So this Knapheide Service Body will fit your Dual Rear Wheel .. 60 Cab to Axle (key measurement) .. GM truck .. I am told by Knapheide that it will fit a longer truck (Cab to Axle) but you would have to add something (say a platform for a welder or compressor) to take up the distance between the body and the cab .. Asking $4000 or best offer .. body is very clean .. doors are immaculate, locks work and have keys .. call with any questions but don"t lowball .. we have the ability to load and can deliver for a fee