I used a Pertronix kit on mine, I have used them on other vehicles for well over 10 years, as well as customer engines. Never a problem. A worn out old distributor can cause timing "flutter", it jumps around a bit because the distributor shaft is wobbling, due to worn bushings and such. With a Pertronix kit there is nothing touching or riding the shaft anymore, and timing is rock solid, no more flutter. It does NOT help with worn or sticky advance mechanisms, those you have to fix if they are going bad.
It's hard to beat a new distributor, but I don't know how you can be sure it will be curved right for your engine. There is virtually no quality control left in this industry.
