I got my 53 mocked up on the 4x4 frame,. the frame was an extended cab. I now have about a 9.5 inch gap between the cab and box. I know the wheel base measures out at 122.5 and i have to cut it down to 116, but that will still leave me with about 3 inch between cab and box. I like the way it sits on the frame, easy to lower the front end eith the torsion bars and the rear frame rails don't have to be cut, but cutting about 8 inches out of the frame make my truck look funny at 115 inches or affect the driving of it. any info will help. oyu guys are the best, lots of very usefull info for projects like this.
