EDIT:
Upon closer inspection, Im wondering if a smaller wheel will fit that setup or not. What do you guys think?
OK,
No, the only wheels available for the 5/10 lug on 7.25" circle are the 20", 19.5", the 22.5" wheels.
You can get some low profile tires on the 19.5" wheels, I think they look small and a little silly on a 1.5 or 2 ton truck though.
If you want even smaller wheels then their is an 8 lug version of the same I-beam axle from a P30 and they use 16" dual wheels.
Grigg