First off, I have no idea what any previous owners did the my 4Runner. When I bought it there were already 285-75-R16 tires on my '96 Liminted.
I put the same size DuraTracs on it when I had to replace the no-name offroad tires that came on the truck (about 2yrs ago). There is no rubbing on my truck, but it is very close in several places. The exception is if my bumper falls out of position (the previous owners attached a brush gaurd to the bumper).
Comparatively, the asphalt holding ability of the DuraTracs far exceeds the previous tires. I never had a chance to test the old tires in proper offroad. However, I spent most of the last year in the MS Delta and had a chance to drive in the mud. Both myself, and the locals I was with, were incredibly impressed with my truck's ability to get itself out of situations. This was primarily attributed to the tires, because I certaintly don't know how to drive in mud.