Has anyone else actually done the "small HEI" conversion? I have, and it's not simple or easy. Unless you have a lot of machine tools and several years' worth of experience using them, it's not something I'd recommend trying. It involves shortening the housing, fabricating a shaft extension to drive the oil pump, and changing to a different drive gear. I started with a third world clone of the S-10 distributor and spent several hours in the machine shop modifying it. Then I trashed the no-name electronic parts and bought "new old stock" Delco-Remy items to replace them.
Here's one to start with, if anybody's up for the challenge
www.ebay.com/itm/133580523350?Jerry