Who makes a good E-core coil?

"Small cap distributor" => "8-pin HEI module". Why aren't you using the GM "external coil" that goes with it? You just grab the GM factory cable that connects the two, plug and done. While in there, I also grabbed the knock sensor & module, but that is for a Holley Commander 950 (or Megasquirt).

If you want to pay a lot, buy an aftermarket coil, either red or yellow depending upon who you want to give your hard-earned money to. To stay Mopar, grab the e-core coil off a Magnum engine (until ~2001, also on Jeep GC I think). It is probably as good as the red & yellow ones.