First post here you mentioned replacing the whole distributor. Was that a brand-new or otherwise known-good unit, or just a used spare you had lying around?

Asking cos I wonder if the ignition control module (ICM) inside the dizzy may have failed. Sometimes when they start failing they don't go totally dead but can burn-in a bad dwell (which is how long the coil charges between sparks), so you'd still have spark but not enough oomph to start and/or run well at idle or certain RPMs. Also a good idea to replace the capacitor/condenser at your coil, since that going bad can contribute to the ICM getting cooked.

Also not sure that .43 spark cap is correct, seems large but I'm not sure what the proper gap spec is for the 2.4L.