My reasoning for the frame swap is this . The bump and dent side frames have a ton of flex. Welding cages to them is tough to do and not have the truck tear itself apart. Rear steer is hard to package with a swinger. Suspension options are limited to one or two manufacturers. An 80s or early 90s frame has more options for suspension and powertrain. I've fought steering issues with my bump side and I'm still not too happy with it. Bump steer is tough to eliminate with the rear steer.