Mods, feel free to move this to the "Vintage" forum if that's where it'd be more appropriate, but I have some questions about the ignition setup on my 1999 Vintage Sport with S&S 107 and Thunder Heart dual-fire ignition. After having to seek the help of my local V-Twin guru (we both thought the problem was ignition-related, turns out the main jet of my carb literally fell out and was sitting in the bottom of my float bowl!?) to deal with very crappy throttle response, he was telling me that he'd had a lot customers that had come in to replace the Thunder Heart ignition systems on their bikes. He hadn't done much with Big Dogs, but they were apparently a fairly common part used when the "chopper craze" of 10-15 years ago was in its heyday. He suggested that I swap over to the Crane/S&S HI-4N setup in single-fire mode for best performance. I like to do most of my work myself when I'm able, because I want to know what's going on with my bike and don't like shelling out for labor if I can do it myself, so I'll be putting it in. That said, I need to know a few things. A) Is there anything specific that I need to do with the old Thunder Heart ignition module, i.e. is it controlling anything else that needs to be converted/retrofitted? B) Is there a single-fire coil that will fit under the original factory billet coil cover? C) Aside from a 2-into-1 pipe to replace the Hooker Header longshots, the engine is as-built from the factory. What should the rev limiter be set at?