Ditto. Don't fool w/ the older 4-pin HEI module. Take an 8-pin HEI module from a 85-95 GM V-8 truck (cars to 93). The module is within the "small cap" distributor. Also take the "external coil" and the cable that connects the two (simple plug-n-play). Snip the red (+12 V supply) and wht (tach) wires as long as you can. You can buy all above new from TrailBeast if you don't mind paying more. I like junkyards. I have even shed a tear for the poor GM vehicle as I molest it.
You can't easily use the GM coil w/ your current ignition system, due to the connector issue, so just stay w/ your current coil until ready to do it all. Sure, you could use the GM HEI module with any coil (preferably an e-core), but then you need custom wires and connectors, which is the headache.
