I've run the numbers, and with 35's, 4.56 gears in the axles, I'll be at 2250 rpm at 70 in 5th gear (0.73) and 3000 rpm in 4th (1:1). These trucks (modern 1/2 ton v8s) cruise at under 2k rpm at highway speeds with stock gearing and tires, so I figure the bump in revs will account for the tire...