This is odd. Everything I've ever read here suggest 31x10.5R15's work jsut fine on the stock alloy(aka "LS") rims.I've run a variety of 31x10.5's on several of my Montero's with never a problem, both nearly always they have been used with already several 32'nds of wear. For sure BF Goodrich All Terrains and Toyo Open Country's seem to have no issue. I also though severla have run various mud terrains this size with no issue on a stock set-up (stock rims, stock height, etc).

I did however purchase my first brand new set of 31x10.5's for my 89 LS a few months back, but still havent gotten them on the road yet as I'm still screwing around with rear axle upgrades. They are the new(er) Goodyear Wrangler DuraTracs with the side knobbies on them. I'll monitor the situaiton carefully and report back in the future. I'm hoping with what I paid there isnt an issue.

Jim