Misfire at cruise, popping/afterfire at 3000RPM

Yes, dual x-pipe exhaust. It's hard to tell whether it comes out of both or one, but I will say it did this with open headers as well.

I'm running a light blue Mopar ECU from Halifax and when I bought it, I bought two from him. I've swapped this one out for the other, and the same problem. The stock coil that came with the car swapped for an MSD Blaster 2, same problem. New distributor, same problem.

For a while I was thinking it could be getting too much advance, but I checked my total and was only getting 24 degrees all in at 2800. Initial is 14BTDC, so for some strange reason I'm only getting 10 degrees mechanical with this distributor (??). I talked about this in another thread, but I felt like we were getting sidetracked, so I wanted to come back to this thread and not have a hundred different threads about the same car/problem.