[dirtyjim]

i did one back in my early 20's, it was on a 89 chevy with a camper shell. its actually pretty easy to do, I did most of the cuts with a sawzall. I used camper boot to seal it back up then made plywood panels for the floor and sides of the cab that I covered with carpet.
I didn't do it for more passenger room it was done to help show of the wall of 8 15" subwoofers in the bed of the truck