do i need to run a resistor with the ptx conversion kit? the car is a 63 mercury with the 390 if it makes a difference. thanks. -joe
Not to my knowledge. I put one on my '68 Galaxie w/390 back in '01 and it has given me no problems at all.
Pertronix states that if it originally had a resistor that you should keep it hooked up. Personally I wouldn't use a resistor, the Petronix is a kick ass ignition so let the juices flow and use it to its potential. You may want to use the pertronix coil , around $25 from Summit, this will ensure the proper resistance with the coil.
I installed a pertronix ignition and coil on a 350 SBC and left the resister on as the instructions said. The car would cold start and run fine until I shut it off. It would not start again until it had set for 15 minutes or so. I by-passed the resister and no more problems! Been running fine now for three years.
What the ptx instructions say (this is the Ignitor version) .....is that you must have a combined resistance of 1.5 OHMs in the coil primary plus the ballast resistor. If the coil primary resistance is over 1.5 OHMs, the ballast resistor would just be cutting your ignition power. I have heard of people cheating this down to about 1.4 OHMs and getting away with it. Go lower than that and you will probably get to try out a new one....
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