I put an RH42 (A500) in my Dart GT, and used the simplest controller - two switches. One activates the overdrive and the other activates the lock up. It was simple, easy and gives you lots of choices at higher speeds. Over time I have found that I don't even think about hitting the switches - you hear the rpms and just reach down and hit the button(s) without even really thinking about it. Until you get used to it, you'll probably roll to a stop without turning the lock-up off and kill the engine, but it's not a disaster.