I've run 255/85r16 Toyo MTs (33.5"x10.5"). Then 315/75R16 (35s). Now Ko2 34x10.5R17.
Skinny tires are lighter, track better on road, better MPG (less rolling resistance), easier on suspension/bearings/joints. However, I think you need a tire with 8-9" actual tread width (most you need to...