what to know if 15x8 or 15x10 wheels will fit on my 2000 frontier CC 3sl t-bars cranked. want to go with 31x10.5 or 31x12.5 will I need to cut the fenders?

15X8 is what I'm running right now. I wouldn't go 15x10 due to the amount of sidewall that would be unprotected. It also has a bit to do with the rim's backspacing.

what is the best back spacing for 15x8 with 31x10.5

Right now im running, I think, 3.5" or 4" of backspacing. I'm running 32x.11.50 tires and have minimal rubbing with this setup.

Oh yeah! to the board!

Thanks for the help. I should be getting my front bumper this weekend and hoping for new wheels and tires soon.

15x8... A 10" wide rim puts a pretty good amount of stress on the steering and suspension. I would recommend a 10" or wider rim for a SFA rig only.