well, I think I will stick with single rear wheels, I don't have the money it takes to do the swap either way.

 

drw inner trie/rim is going to be too close...w/out spacers to get them away from framerail, that is the reason for the cab/chassis narrow frame behind the cab

77 high boy crew cab, was a dually, now it isn't

outer drw does not extend too far out, actually a set of bushwacker flares would have covered tires, I sold the drw fenders and then sold the rims, have a extra set for sale though.....pic of drw w/out fenders




pic of drw w/ fender..77 crew cab 4x4


78 f250 crew cab 4x4 w/ spacers to accomadate drw...set is available..

 

You could find a utility bed. Last year I saw an 80s F350 with a camper on a utility bed. It was quite a rig. The camper fit like it was the stock bed and it covered up the dually tires. I know it isn't a factory bed but that guy had tons of storage space. But then you are probably pushing the weight limits of your chassis which hasn't been mentioned yet, along with better braking if you are hauling that much weight.

 

This:
Old Ford Crew Cab Community, Pre 1980 Ford Crew Cab owners community and information source.

 

what size spacers would I need? and do I need the bigger brake hub assembly? Could I use longer wheel studs?

 

Where are you located? I have the whole set up available, rims/axle /spacers in NJ...

 

probably 18 to 20 hours of driving from where you live, I live in the Northwest corner of Alabama. and I'm kinda not willing to drive farther than Tennessee or Mississippi.