There is one situation in which lateral proximity might matter. I put 14" rims and tires on 98 Burro
. I had immense amounts of space on the driver's side both vertically and side to side in the wheelwell. Different story on the passenger's side. The wheelwell that side is actually molded into the inner shell and of course the mold has draft (slight taper which avoids molded parts trapping or sticking to the mold) and the upshot in the right wheelwell area is that the inner wall of the wheelwell approaches very close to the sidewall of the tire at the radius below the tread (maybe 5/8"). I check every so often and so far the "activity" of the torsion axle
has not led to scrubbing the sidewall on the inner vertical surface of the wheelwell. How thick is a human hand-- 1 to 1-1/2"? I think you're OK particularly if the inner surface of wheelwell is plumb or perhaps I should say parallel to the tire and rim. They're already on there so a bit of observation is warranted before taking on more expense for tires with a lower load rating. Only a result (and an opinion) from a similar quandary not long ago.