I have bfg r/ta's that are 295/50 15 rear and 235/60 15 front. I had to special order them and wait a few months but Tire Rack makes them once a year for a few weeks in the summer. I was in contact with the Tire Rack Guy on the vendors site. Halibarnd 15" wheels and assembly is not complete so don't know about clearance as yet. They are mounted on the rolling chassis now.
In response to Craig S.: Re clearance for 295/50 bfg tires; I see that there is about 4" clearance now without body and engine, but I can see that it may be an issue if rear suspension, std width irs, moves that far. Any idea if this may be an issue?