As you know I don't like to throw parts at a problem, but this may be one of those times
i hear ya
As long as you are convinced it's not a cam / drive problem, nor a distributor gear problem, my guess in no particular order.............
yep
Pickup/ pickup coil, either loose or coil going bad, look carefully for debri (metallic particles) or rust around the pickup / reluctor
pickup coil is clean and the coil ohms per spec.
CAREFULLY examine the dist. for shaft play, both in the shaft and mechanical.
its actually tighter than most ive had! probably because this thing only has 105K on it.
THERE WAS (I think orange?) a Mopar ECU that did a similar deal some time ago on this board............or at least that's what the member claimed cured it.........replacing the ECU