We used to put 17" tires on our 3/4 tons with 4.56 rears and run them 65 to 70 all day long. If your engine is in good shape, running her at 3000 won't hurt it a bit. It will get noisy and don't expect very good fuel mileage because your vehicle isn't aerodynamic. If you gear the thing to turn 2000 at 65, you won't have enough power to run it there except down hill.