JimmyZ: I did check for spark at the coil wire. I pulled the single wire that goes from the coil to the distributor and laid it on the fender and cranked the motor. Good looking spark there.

When you say that you are laying it on the fender and getting spark that's odd. The plug should not ground because of the paint.

If the coil is making a spark at the main coil wire then it is downstream of that part. It should beone of the following ... rotor, dist cap, fouled plugs or it might be that you have a bad coil which sparks under atmospheric conditions but has become too weak to jump the gap under compression. I was once stumped by a coil that did just that. It might also be possible that your dizzy has so much slop that the pertronix pickup isn't in close enough proximity to the sender to get a good signal. A sloppy distributor can even cause a rotor machine the cap giving rough running or no run. (extreme) Wiggle your dist shaft and check your parts for "wear".

First thing I'd do is swap the plugs and dist cap given what you've described. (Just to experiment)

Times like this it's nice to have a backup distributor with points just to try some "plug 'n play".

2c

Jim

Provided you've maintained the correct airgap between magnet ring and sensor, if the voltmeter doesn't deflect to zero it sounds like it's failed. Maybe because of the coil resistance, maybe not. It would be cheaper to revert to points than replace the Pertronix, but I would call them to confirm before tossing it in the trash. BTW, if the coil reads 2.5 ohm and not the listed 3 ohms, I'd replace the coil too.