I have well over 40,000 miles on onr Pertronix unit , it's important to measure the primary resitance of rhte coil and match it to the application , they have the valvues n the instruction sheet .

Didn't add any noticable power but made a HUGE improvement in starting especially after a hot soak and the idle is smmother too .

-Nate
There is no problem so difficult it cannot be overcome by generous application of brute force & ignorance