Most of the big truck frames are straight rails 34" apart so you best bet is leave the frame and change the running gear, like Grigg did with his new F@rd. Your biggest stumbling block would be the front axle witch is narrow on our old trucks. I am not sure about getting as ambitious as Grigg in narrowing a front axle but if you are good he has proven it a viable option. I have been thinking about using a wider axle and having a good body man section my fenders if it can be done without changing the look of the truck. With my 56 I think the factory has widened the front of the heavier three axle trucks them selves. After studying pictures I have noticed the heaver three axle trucks to have a larger bulge to the front fenders. Anyway I think I can widen the front fenders and keep it very subtle and a wider front stance will be a plus in the handling department.
