shortbus4x4
Expedition Leader
It will be much much easier to move the axle on the frame versus moving the wheel wells on the box. If you don't feel comfortable doing it yourself talk to a truck shop or mobile truck guy. It is pretty common to do this on commercial trucks. If you don't want or can't move the truck right now because of the box see if the truck shop will let their best mechanic come do it on their time or his. Just make sure he has done it before and knows what he is doing, don't get some guy who just started and this is his first job.
You could go with a bigger box but if you are happy with what you have then run with it. There is something to be said for putting a light load on a HD chassis when you are running rough roads far away from parts and mechanics. My grandfather built a custom camper in the early 70's using a 27' Winnebago fifth wheel trailer and a 1970 Ford 700 Cabover chassis. He took the axles out of the trailer, jacked it up and backed the truck under it. He then extended the rear frame, moved the rear axle and bolted the two together. It was a double frame motorhome. He ran singles in the rear and modified the rear springs due to it being lighter than what the truck was built for. He drove the Alaska Hiway 16 years in a row with it and didn't have any serious issues. I think he put 270k on it before he sold it too me when he couldn't drive it anymore in 2005. The first motorhome he drove up in the late 60's was a stick and staple on a IHC chassis. It broke the front springs on the way up and he had to junk it when he got back due to the body coming apart. He was very disgusted with it so he built his own that would last.
You could go with a bigger box but if you are happy with what you have then run with it. There is something to be said for putting a light load on a HD chassis when you are running rough roads far away from parts and mechanics. My grandfather built a custom camper in the early 70's using a 27' Winnebago fifth wheel trailer and a 1970 Ford 700 Cabover chassis. He took the axles out of the trailer, jacked it up and backed the truck under it. He then extended the rear frame, moved the rear axle and bolted the two together. It was a double frame motorhome. He ran singles in the rear and modified the rear springs due to it being lighter than what the truck was built for. He drove the Alaska Hiway 16 years in a row with it and didn't have any serious issues. I think he put 270k on it before he sold it too me when he couldn't drive it anymore in 2005. The first motorhome he drove up in the late 60's was a stick and staple on a IHC chassis. It broke the front springs on the way up and he had to junk it when he got back due to the body coming apart. He was very disgusted with it so he built his own that would last.