Yeah, a tubing cutter is definately the best way to go... You'll be assured a nice, clean and dead-on cut. I personally haven't seen any that large, but I'm sure a plumbing supply place or Home Depot might have 'em.

Stormy - yeah, I hear that. My 265/75R16 TrXus is a seriously tight fit, but fully aired. I don't think the Gibson is in my future, but the Nissan one might be... I'm not really into putting the spare on the roof, that's just a pain in the ass, and I'd rather keep what mileage I do get...