I have an IO540D4A5 engine that is having issues with the Slick Magneto. I have to decide which way to go. I also have the older Lightspeed that is functioning fine. The current Slick is a 6351 with an impulse coupling that I am not going to re install. I can either use a 6350 standard mag or a 6393 that will retard the timing. I dont think I need it retard timing as the Lighspeed automatically does it on start. The other option is to just use two new Pmags and be done with it. I just spent $700 on lower fine wires so I am leaning towards a new 6393. I do have two totally separate electrical busses and alternators on my F1 now. I had e mags on my last plane and it worked fine