They don't allow the tire to properly make road contact being on that small of a rim, they are 12.5 inches wide, so I would go with a 8.5" at least to be completely honest...that being said, I've done it on a few vehicles with no problems, and I worked in the tire industry for 7 years
Darin
01 Xterra SE 4x4
COMING SOON:
Intake mod, timing belt, hoses, belts
Wish list:
PML, EFan conversion, shocks, 32" tires, and eventually UCA'S