The HEI comment was tongue-in-check since many people upgraded to an HEI ignition. Cheapest and simplest is the 8-pin module used in the 1985-95 "small cap" GM V-8 distributors with its coil and connecting cable. A Mopar e-distributor can trigger it (many posts). Another advantage is that some aftermarket EFI kits can adjust spark timing thru it. If an old points distributor, simplest is the Ningbo "ready to run" distributor (~$60) and e-core coil ($30) which is drop-in for a small-block or big-block (none for slant). There are also custom HEI distributors for much more (>$300).