[CC69Rat]

Yeah, a wide housing stepper is going to be a challenge on a 4/6. Say you ran 20's .. you'd be around a 20x8.5, possibly 20x9 with 5.5" BS. (the wheel is going to look a bit narrow on the outside. Not a lot of wheel lip to the outside. )

So -- in this example, the 8.5" wheel Where I have the narrow axle housing, I'm running 4.75" backspacing. (check my stepper build thread if you want to see) Because the 72 axle housing is wider, you'd need to offset this difference in the wheel. Ex. .. the wheel sits BACK further under the truck but it takes away the lip you see on the outer edge. So, your combo would be around 5.5" BS.

Some guys run wider wheels on the steppers, but mine, I kinda like a little more tire.. I don't really like for the wheel to be wider than the tire if you know what I'm saying? Kinda hard to describe.

55.5" early housing
57" late housing

.75" wider on either side so say I put my wheels on your truck they'd stick out .75" more on either side. I think you get the idea. Just trying to help .

Coys makes a 20x8.5 with 5.25 BS that would probably work for you, .. but you might have to trim the fender lips a little.

You could also swap to an early rear housing, but that means early 5 lug axles (which are likely going to be aftermarket) Honestly if I were you, if you're planning to swap to a fleet bed, I'd just wait. You would then want a 20x10 with 5.5" BS. 6" BS if you're going really, really low or wider tire.

Hope this helps.