Hi, hope this reply is helpful. Those later HEI distributors have the coil on the distributor cap. That 3-wire, 2-prong plug plugs in to that coil. I've been using one in my truck for years. First one was a junkyard pull, worked, but took slow-me awhile to recognize that the centrifugal weights were partly frozen; I thought at first it was just a weird smog-era advance curve. Bought a new aftermarket one a while ago - I think these are a one part-number fits all, so could probably use some advance curve tuning, but works well enough for now. Nice not having to replace and adjust points. If you go this route, you'll need a full 12 volt supply (the stock ignition supply has a resistor). You may need more initial timing advance as well. Good luck!
