Steve,
The first thing you need to do is identify your wheel size and capacity. If you have the Acruride 8.25x22.5 wheel that came on a number of 2006 MY, you are limited to 125psi cold inflation.
Something to keep in mind, in 2018 Michelin released a Technical Bulletin repealing its approval of installing 315/80R22.5 on the 8.25 wheel. In addition, they reduced the published load carrying capacity when installed on an 8.25, other tire manufacturers have since followed suit.
As for clearance, you’d need to actually mount and install the 315s to verify. Some have been successful while others with similar coaches have had issues that required modifying the air bag mounting plates. Those with longer wheel base coaches have been more successful.
I was considering 315s and decided that it wasn’t worth the hassle of mounting, trying and possibly removing the 315s, especially with the reduction in load caring capacity.
I went with the Continental HSR2 295/80R22.5 for steers, at 120 psi the HSR2 carries additional 255 POUNDS per tire over other brands of the same size. Being and member of FMCA, the Continental is available through the FMCA tire discount program.
I went with Toyo M144s for driver and tag.
I run Centramatics on all axles with no additional balancing required, this has produced a very smooth ride.
-Scott
Corrected the following:
carries additional 255 psi per tire, S/B carries additional 255 POUNDS per tire