Hi all, it looks like I am working my way towards every body style chevy truck made

I got a ‘70 c50 box truck awhile back from a guy and I talked to him yesterday and asked how his 55 lcf was coming, long story short, I am going to go get it in a month. It has been an year since I saw it and what I am thinking is putting the body on another running/driving chassis to have an updated work truck. He started down that road too, so I don’t recall what all is left of the truck other than he did tell me yesterday that it will roll.
So, my questions:
1. What is the track width on the front of the 55, he says it's a 2.5 ton, if it matters, I think 20" wheels. The chassis I am thinking of using is an S line IH with air brakes, so I am a bit worried that the 55 is too narrow.
2. Are there any special parts or good reasons to keep the original chassis?
3. I think he said it was a winch truck, what engine and trans would it most likely have? I don’t think it has the winch anymore.
Any thoughts or ideas will be appreciated,
Thanks,
jason
http://s1229.photobucket.com/albums/ee466/macgyver37/55/