What is the difference in the width, backing plate to backing plate between a dually rear diff. and a single wheel? is there a difference in the front diff as well? Thinking about making my w250 a dually and trying to figure out what all I would need. Anyone here have a roller with the diffs and wheels, I'm located in north eastern Washington State

 

Its maybe 2" difference to get to C&C width. More like 7" to get to dually pickup width.

If you added a 1" spacer to each side, inner dual should clear the leaf spring. Need bigger wheelstuds to match the dually wheels though. Front is just hub differences; axle housing is the same.

Edit: i have dually parts trucks and keeping my w250 singles. Stronger tires is all it takes. I haul 2ton in the bed whenever.

 

Isn't there a difference in the wheel wells? What about the length of the wheel studs?

 

The factory dually bed has larger wheel well openings and flares. A flatbed is a better option for the weight these trucks can haul.

The factory dually studs are 5/8" and longer. Depending what wheels you use, and stud vs hub pilot, you may want to consider 9/16" .

 

The bed is definitely different, but I plan on going to a flatbed if I can get the diffs with 4:10s and as u2slow has stated the rear diff is wider on a dually rear at 60 inches vs 53 for the swr rear

 

Be aware that there is a narrower Cab and Chassis dually axle and a standard pick up truck bed style dually axle, when you are out shopping.
With a flat bed the C+C axle might be a better choice..

 

Oliver is there a difference in frame width between the cc and a standard swr frame?

 

The frame width is the same between the two.

The length can vary from pick up truck beds trucks and is often longer.

The actual thickness of the metal in the C-channel frame is usually a bit thicker on the '72-'93 C + C trucks, than standard SRW, or shorter wheelbase rigs of the same similar year.

 

My 75 and 78 c&c frames are the same width and same spring hangers as the pickups. Also 7" channel instead of 6".

Its ford and chev that usually do a special narrow and flat c&c frame.

 

Thanks Oliver and u2slow for the info, at least now I know what to look for. There is a rumor floating around that an old boy has a few of these stashed in the woods north of where I live so I think I will spend a few days trying to run that down.