Is this a bad idea or not? I'm not really interested in buying new rims but I do want a bigger tire. If it's not possible to run this combo, how do you go about machining the center hole on a Ford rim bigger?

The rim is to narrow and could possibly slip a bead very easily with those tires.  Also they would rub severely on the frame.  I have ford rims and i just grinded the whole bigger (extremely bad idea cause they were near impossible to balance) but they work

Yeah, I didn't think it would work. Hmm, I think I'm going to have to find someone with a really big lathe...

Ya a laythe would work, but you could also measure the hole, and buy a metal cutting hole saw that size and just use a high speed drill...thats what i planned to do but the hardware store didnt have the size i needed...i think it was like 4 1/4in or something

I don't think that would work, because you need a center point to start from...how are you supposed to determine the center point if you have nothing there?

I have a 31"x10.5" tire mounted on a stock rim. Fits no prob... This is actuallt whats called a poor mans bead lock and has been done many a time to "PREVENT" the bead from slipping off the rim. Now the only factor is that you will have a tire that may "round out" and actually be taller than the actual 31" height due to it being narrow at the bead.
As for the ford rims... find ones off an earlier model 4x4 with locking hubs as the 2wd ford rims you will have to make the center hole larger. You can also try rims from a jeep CJ... (no a tj or yj or xj will not work) earlier dodge 4x4 half ton is also the same bolt pattern and wheel center... Kia is the same as well.
I would not recomend making the center hole largeron the 2wd ford wheels by hand as you may not get it round or may go over size and that could be DANGEROUS due to putting alot of stress on the wheel bolts and possibly bending them or snapping them and the wheel would go off center and possibly fall off.
Kelly

The rim is to narrow and could possibly slip a bead very easily with those tires.  Also they would rub severely on the frame.  I have ford rims and i just grinded the whole bigger (extremely bad idea cause they were near impossible to balance) but they work

Whateverworks, thanks for the GREAT response! How do the 31x10.50's work on the stock rims, in your experience? Do they rub on the frame alot like museboy07 said?

 

A buddy of mine runs 30x9.50's on stock rims.

The narrower the rim, the tighter it will hold onto the bead.  You wouldn't want to put 31x10.50's on a 10" wide rim, and you'd really have bead problems.

I have wheeling friends with 31x10.5's on stock rims, they're fine, they wheel them, and drive them daily... no problems as of yet, maybe some rubbage on the frame, but nothing that can't be adjusted.
I personally wouldn't do it, I like the wide stance look, and added side stability, but if it's just until you can find something later on down the road, for sure.

I found a pretty good deal tonight. 15" Ford 4x4 rims (5 bolt of course) with Uniroyal Laredo A/T tires on them with 85% tread, all for $500 Canadian. I'll be checking them out this weekend, and if they look good they will be sitting in the garage until I get my 2" body lift on.

PS, they are from a F-150 with automatic locking hubs, but the center hole is the same size as the ones for a manual locking hub, right?

Get yer measuring tape out and see
Kelly

Ford wheels that come on 4x4s do not all have a big enough center hole.  I have a set of wheels off a 90-something 4x4 Bronco with manual hubs and the center hole in the wheels are too small for the trackick hubs to fit through.
I know someone mentioned "earlier model 4x4" wheels......those may have had a different sized center hole, than the later wheels.

Ford wheels that come on 4x4s do not all have a big enough center hole.  I have a set of wheels off a 90-something 4x4 Bronco with manual hubs and the center hole in the wheels are too small for the trackick hubs to fit through.
I know someone mentioned "earlier model 4x4" wheels......those may have had a different sized center hole, than the later wheels.

After market rims fit.
Bring along an extra center cap along to check..
we all carry one when shopping for wheels, Right?

After market rims fit.
Bring along an extra center cap along to check..

I'm not so sure about that either.  I know some aftermarket wheels, that have the 5 on 4.5" bolt pattern, don't all have the same size center hole.  My brother had a set of aftermarket wheels on his Ranger and another guy had a set of aftermarket wheels on his jeep.....the Ranger wheels fit the jeep, but the jeep wheels wouldn't fit on the Ranger, because the center hole was too small.

As mentioned, an extra center cap, or a tape measure, is good to have when looking at different wheels.