Sounds to me like this surely must be a distributor problem, but it could be a "weird" defective module. I used to think modules either ran pretty much or not, but at least a couple of guys on here have had Mopars that ran and not well.....turned out to be the ECU
FIRST thing I'd do is check shaft play in the dist. Get a .008" (inches) brass feeler and check the reluctor gap. Check for strike damage and debri in and around the reluctor. Make sure the distributor connector is "made" well.
Make CERTAIN the distributor is hooked via the diagram. Looking at your mount that looks fine
One of the members on here was good enough to "professionalize" my hand drawn diagram. Not which distributor terminal "as drawn" the 'small spade' hooks to. It MUST be this way