The real question is why would you want to? The rules of times 2 indicates you would need to run at least a 34" tire if you run 17" rims. If you run 17" rims and 31" tires your ride will be stiff and will not allow you to run lower psi. On the upside you will "look good" but that's the last thing you should worry about when building an expedition vehicle. Having owned a 1991 Montero I would recommend going with a 15x7 wheel and 30x9.5 or 31x10.5 tire. Anything bigger will kill your power. I know many will recommend steelies but I would go with a light weight aluminum wheel and light tire (kevlar) to maximize my power.