I have not used a ballast resistor with mine....although I probably should....the civvy vehicle it came out of had a ballast resistor, which I still have somewhere, so I would bet it was designed to be there....though I have had mine in there for several years, I have roughly 8000 miles or so on it....2nd cap and first points....only changed the cap because it was WET from deep water racing at FE99...changed it right there...so I havent really notoed any negative problems...but still it was designed for it.....
The Napa part numbers for the civvy ignition cap, rotor, points, condensor, and primary wire are in the parts list in the online manuals section linked at left.
brute4c