I have been using the Moroso mechanical stop p/n 65042 ( modified with a longer threaded rod) for over 8 years now and have been very successful with it. I am slowing about 8-9 tenths on average. I use it to slow down to 11.50 for Street Eliminator and for 11.50 index racing. Electronic and air operated stops aren`t allowed in the classes I run. I considered a plate system, did some research and talked to racers using them and came to the conclusion that my system is best for my combo. I have seen some of my fellow competitors using weight and shift points to slow but again i feel my setup works better. A word of advice: if you use the Moroso setup be sure and use a throttle linkage bracket like one from Jegs etc. so a second bolt can be used to attach the stop as it will tend to move if used only using the carb bolt. As a matter of fact I am going this Saturday to a Test and Tune to get the stop dialed in for my new motor combination.