I am putting a MSD DIS-4 on my car this season and it has a 2-step on it, and I was thinking about the implications of this. Since it drops spark randomly on cylinders, it is going to push the fresh air/fuel mix right through the engine into the header, is it possible that it will ignite in the exhaust? My concern is because I will have dual cutouts about 18" past the collector and really don't want to be shooting flames out from under my car. The cutouts do point downwards, but I just don't want to chance it.

 

So long as you have the tune right your not up on the 2 step long enough to have excessive amounts of raw fuel collect in the chamber and be pushed into the exhaust. Get yourself into the habit of not matting it until the top light on the tree comes on, I and many other have been burned because tree operator did'nt hit the button or electrical glitch. Too much time on the 2 step will be bad on other things beside a few tiny flames coming out hte exhaust. Worst I've ever seen anyways is maybe a orange glow up inside the collectors, I've never seen flames shooting out on a tuned car.