Thanks to misha and abscate for their expertise.

Runs much rougher with injector on burnt-valve cylinder removed. Seems like even at 55psi, that cylinder fires some....?

My shop will do the valve job in a week.

Peter

Updating you nice fellows. Got the car back after 4.5 weeks in the shop. Small shop, covid outages, etc. All put back together, it runs smoother than I ever recall. The engine is calm as a rock at idle, and stays calm as it revs up Several internal parts fell apart as they did the job, so there were...