There is another way to torque the nut to spec:
Use a breaker bar, and STAND on the bar in the appropriate location when the bar is PARALLEL TO THE GROUND.
For example--Let's say you weigh 200 lbs., and you need to tighten the nut to 150 ft-lbs. If you put a tape mark on the breaker bar according to the following calculation:
150*12/200=9
Place the tape mark on the bar at 9 inches from the CENTER of the socket, and place the bar EXACTLY horizontal. STAND (as in put ALL your weight) on the bar directly on the tape mark. 200 lbs at nine inches from the nut equates to 150 ft-lbs.