Posted by Brian in Oregon on April 29, 2000 at 17:01:49:
I'm looking at a post I printed and saved last December.
First, the largest normal tires that seem to have little problem, other than perhaps bottoming on the front fenders in EXTREME articulation, are 11.00x16's. I've seen some slightly larger tires on some M37's, but they would definitely rub on the underside of the fenders during full compression w/o a lift. In my opinion, 11.00x16" tires could probably use a 1" lift to keep roughly the same amount of articulation clearance as the 9.00x16's had. Snake River makes an adaptor plate to run 11.00x18 Gama Goat NDT tires. Looking at the photos, they do soak up fender clearance for full articulation, but again, in my opinion, a 1" lift would resolve this. The nice thing about these adaptors is that it spaces the wheels further apart, giving a bit more side slope stability.
But back to the info from last December...
J. Calhoun put huge-by-large 44"x18.5" swamp style tires on his M37. He did a 3" body lift and moved the front axle and inch forward, and removed the rear fenders and front fender brackets. This is probably the most you can get without extensive work. He says the stock motor will not spin these tires in deep mud, but then, they won't bury themselves either.
Looking at the photo of his truck (which I can't find on the web anymore), it looks big and tough, like a mini-monster truck. But it sure doesn't look original or military. Depends on the look you want.