from the tool bin. Snapped a 17" 3/8" drive breaker bar taking the stock pulley off. Surprisingly, a 1/2" drive breaker and 12 point 19mm socket did the trick. Re-tightening the UR pulley to the desired torque took a friend standing on the brakes while I did a double leg press on the breaker bar to torque to specs. The engine revs so much more nicely now. This mod definitely goes in the better bang for buck category, IMHO. Sometimes, maximizing the power available is easier than trying to make more.