Some Walmarts will, some will not , I have personally had two that would only mount OE sizesNot entirely true. You can show up with your tires and your wheels and they will mount and balance them.
real issue here is the suspension.
Even 225/75R16s will rub the pinch weld on sharp turns if you running the notoriously mushy OE style stock or “whatever was cheap” suspension.
and yes I always haul mine into any tire shop on a trailer ( the wheels and old tires to be changed)
I started lying and telling them they were going on a Tacoma or Wrangler and no more issues