We just put the Holley Sniper on my sons 400 Dart. At first we ran it with the normal dist and MSD controlling the timing. Its a stock dist I recurved. About 2 weeks ago we went and put the Holley Sniper locked dist in it and changed it so the Holley Sniper module now controls all the timing. And of course we put in the timing curve we like. But you can change the timing curve to whatever you like that works best for your combo. He is very happy with the system and we have done a few fine tuning on things like the initial squirt from the injector at key on as we have played with that some so its not to lean or to rich at startup and so it starts up without touching the gas pedal. You can program your IAC settings also so it starts easy and for the idle you want. You can do a ton of programming with it. Some things you can change with the little hand held screen and other things you can take the memory card out and put it in your home computer to make changes. So far we like it and have had no problems with it. We still use the MSD ign but have the Holley Sniper module controlling the timing. You just wire the dist pick-up ( looks like a hall effect on the Sniper dist) to the Sniper module and then the Sniper has a wire that goes to the white wire on the MSD box to fire the coil and control the timing . Ron