Duel point/ Tech drive

Interesting and seems like a keeper. According to the Direct Connection Ignition Bulletin (printed as Chapter 19 in the Engine Speed Secrets), the only factory tach drive distributors were for the 440 and 426 cid engines. Therefore, my guess is that yours is a Hustle Stuff or Direct Connection predecessor to the magnetic pickup tach drive distributors.

If it's internally setup in the same manner as the later ones, then it has a very quick advance to roughly 1000 rpm, and then adds just a degree or so every 1000 rpm after that. This curve is hard to beat at high rpm.

If it was me, I'd map out the advance curve just as it is, on the engine, in the car. This is because because if it has that fast advance in it, you can't set timing the 'normal' way. So while its running sweet, measure it. Get a timing light, and write down the timing for idle and then the rpm for every degree or every two degrees as you rev the engine. (Use your hand or the idle speed adjustment screw to bring the rpms up). Then you'll know the curve, and also have a way to reset it to a known good baseline if you ever do remove the dizzy.

I've set single points, and they're not that big a deal. The dual points is reputed to be a pain to set, but since I haven't done it, I can't verify. There may be some extra dvice on setting the dual point dizzys in Chrysler's Master Technician Conference. There's an online archive of them at the www.imperialclub.org under factory literature. Basics would be any late 60's Chrysler shop manual. Again, while its running sweet, might want to measure the dwell and point gap for future reference.