A lot of great feedback. I just wanted to mention checking firing order on the plug wires and make sure you didn’t throw a weight off your pressure plate.
Did you have the pressure plate balanced?
I had this problem with an imbalanced flywheel and it shook the side view mirror. Also disconnect your belt and do a sort test without turning the alternator. They can produce a very large vibration.
Been there with the pressure plate...it does happen...and its a "pronounced" vibration ...I had the car idling in the bay in a shop I worked at, I revved it up, it shook so bad people standing around were like "what the hell...?"
