GM HEI mopar dizzy hybrid

There are several factory GM HEI module types. See the megasquirt site for much info. The 8-pin is simplest and best wiring, if you use the GM external coil that goes with it (TrailBeast kit or junkyard). You can pay much more for a module with a red (MSD) or yellow (Accel) label if you want, and they are happy to take your money. Don't know if you get anything different. The spark from a standard module is strong enough to hurt you. I think better to put extra money into a spare module for the glovebox.

Re distributor springs. I don't care what the distributor does since I plan an engine controller for all my cars (Holley Commander 950), which can command spark advance, and is real simple with an 8-pin module. It can also rev limit by retarding spark at high rpm (I recall).