With a bolt circle diameter that small, I don't think you would want to run a wheel that large.

The P6 had 22.5's, depending on GVWRs. I'll have to dig around for hub specs though.

How about these bad boys (19.5")?

 

You already have steelies now right? Because the inside dual will remain steel, as the hub land cannot accommodate an aluminum inner and outer. So you will only need four aluminum wheels... two convex polished (front) and two concave polished (rear).



If you like the classic round hole, then search for Alcoa part numbers 761001 and 761002. If you like the star spoked alternative on the white truck in my earlier post above, then the Alcoa part numbers are 761011 and 761012. You wil need two of each part number of a given style, as the 1 indicates a polish on one side, and the 2 indicates a polish on the other.

 

ah ok awsome
and yes i have 4 seelies now. why cant the hub acomdate 2 alum? just curious

 

A hub centric wheel centers the wheel on a hub land that is machined to fit a close tolerance of the wheel opening. The hub itself cannot be entirely machined to that dimension, otherwise it would be very difficult to pull wheels on and off. So the hub is tapered, and usually fluted as well. If you can recall sliding wheels on and off a full floating rear hub, you might be able to visualize the flutes I'm talking about.

Where those flutes, and the corresponding but less visible taper end inboard, is where the machined land begins that has no taper, and that is of a specified dimension just shy of the wheel's specified pilot bore. The width of that land is not wide enough for the thickness of two aluminum wheels. They are just not made that way. To do so would require much longer wheel studs, and the corresponding leverage on those wheel studs that would make the wheel retention less durable.

If you see instances of doubled aluminum dually pairs on hub piloted applications in light trucks (the 3500HD is considered "light"), then it is highly likely that the outside dually wheel is partially "hanging" over the machined hub land, and the wheel center bore is unsupported at the outboard edge... literally floating over the tapered and fluted portion of the hub.

This is not good. But usually, the people who do this don't use their dually's commercially. They are just for show and ego. But not the safest practice all the same.

There are some medium and heavy duty applications where inside and outside rims are aluminum... but I have only heard about them, I've never seen them. However, in working with light and medium duty chassis cabs, I have never heard nor seen any application, be it Ford, Chevy, or Dodge, where the hub land was wide enough to accommodate two aluminum wheels at once. The design is inner steel, outer aluminum.

 

ah ok, awsome that makes sense