is this rim too big?

ok so i have a piza cutter (BFG 33x10.5x15 MT) and I was looking to get those AR 767s. I went to Town Fair Tire to get a quote on the wheels for a 15x8 and the guy there said that the rim I have now (stock 15x7) is too small as it is and was I sure that I didn't want to get the 15x10? is the 15x10 too big for my tire? I though 15x10 was for 12.5 wide tires? I mean if I can get it I probably will but I just want to make sure.

I have 33x12.5's on the stock 7" rim...with no problems.

Lots of people run 33x12.5's on 8" rims, also w/no problems.

For a street application, the wider rim is more stable, but for the X and off road, a good sidewall bulge is fine, and even with the 7" rims, the bulge is merely subtle, not large.

For 33x10.5's, the 8" rim is fine and dandy eitherway...I'd get the 8" rims, it gives you room for expansion, and will hold the 10.5's with plenty to spare.

Wider rims also impact your turning radius, etc...so the X doesn't like too wide a rim anyway.

Also - you want 5.25" of backspacing and 40 mm of offset, or as close to that as you can get.