Slant six ign

Sounds like the OP is wondering if there are after-market distributors. I have never seen one, but you can upgrade your ignition system using a factory distributor. For the early points distributor, I used a Crane Cams XR700 on my 1969. It fits a wheel with slots over the points hex cam w/ optical pickup. You can still buy on ebay new. But, it keeps the ballast so isn't HEI and I had the optical pickup fail on one (in my 65 Newport). For HEI, you can fit Ignitor II or III. If a later electronic distributor, you can trigger a GM 8-pin HEI module. Also use the GM external coil which connects to it via a GM cable. 85-95 GM V-8 trucks in junkyard or buy the kit from Trailbeast here.