I have my car wired with the traditional Ford "jumper" around the ballast resistor - with a lead off the starter solenoid. When the resistor failed, the engine would fire in "start" - then shut off when the key went to "run".

An occasional "infancy failure" doesn't usually get my goat - but the second resistor failed in less time than the first. GRRRRR. The MSD part has never missed a lick - its just a fixed value, heavy duty resistor - .88 OHMs.
UncleAud - When I brought my outfit home (a multi-hour trip on a 104° day) everything under the hood smoked. The power steering reservoir had been leaking since about 1960 - and the previous owner only knew how to add fluid. Even after I got most of it sopped up, the ballast resistor would smoke from the oil contamination. I took it off, opened the cover (it was the original Ford part) and washed it with petroleum ether (starting fluid) several times before it got replaced by the new ignition. There was smoke but never any fire.
Steve Metzger Tucson, Arizona