I almost hate to add this additional layer of choice/confusion, but you could also just convert the existing points distributor to Pertronix as well.
I hesitate because frankly I'm a big fan of Ford's factory electronic ignition. The "Breakerless" (early name) and "Dura Spark" (later name and what most people still semi-erroneously call all of them) are great setups and I converted to that on my '71 using the module that jckkys mentioned earlier. And you've already got at least some of the wiring (can we see pics of what you have?) and that makes going back to Ford almost a no-brainer.
Just thinking that if the existing distributor is in good shape still, it's a good platform for the simpler Pertronix Ignitor conversion. Might depend then on how easy/quickly you find a correct '75 module for your existing harness.
You can identify the later model module by it's Blue "Grommet" color. I don't remember if your '75 is one of those that can be plugged right into the blue grommet module or not though. Seems like yours was different so you might have to use a '75 specific module. But jckkys would know if he sees this and can give you the gory details.
And for my own info, were the '75 modules different between CA and FED vehicles? Seems they were, but again I don't remember all those little details (almost never do!) to make sure everything is compatible.
In spite of it's high quality spark, I have to say Ford never made it easy, what with all the different color modules (like 6 or more of them?) and wiring schemes. Not a bad thing to make them different of course, with different parameters needed and not wanting owners to cross-breed stuff. But after all these years it is certainly a pain sometimes.
There were Yellow, Red, Brown, Black, White, Blue, Orange some with only one wire strain relief (grommet) and others with two. And one I think with three. Only a few of which were cross-compatible with the wiring.
CA calibrations, FED calibrations, and even high-altitude and hot-climate calibrations. Gotta' hand it to GM with their crummy
HEI setup. They changed the internal module wiring and parameters, but kept the same simple "power, ground, tach" wiring scheme on the outside.
Hurts to say that sometimes, but it's true enough. So credit where credit's due.
Speaking of credit where it's due though, have you ever looked under the cap of a modern MSD, Mallory, Accel, and even some Pertronix distributor? A slight variation on the Ford Breakerless/Dura Spark trigger. Fires up on almost every brand of distributor now. Great design.
Paul
