SOLVED
I threaded a pipe plug into the floor of the intake and now she idles like a kitten. So much smoother, vacuum is up to 19.5 inHg and temperatures are much closer.
Swapped the intake for a fresh blue painted one. Wonder if I need to plug the hole in the floor? People say no need to plug, but I left the upper plane threaded hole unplugged and those 4 cylinders were running like dog **** until I plugged it. Lower plane hole is still wide open.
What could cause a dead cylinder at idle (no change in idle when unplugged) low temp on header collector (230F compared to ~450F on other cylinders) and what to check next?
I've swapped plug and wire with neighboring cylinder and there was no change. Cap and rotor are pretty new
1990 stock 360...
How the F do you get this retaining ring out? And what about this weird little fitting? All anyone ever says about rebuilding this pump is that "It's easy". Its not so easy to me.
Update: Had to blow the thing all apart and clean and relubricate since the slides/ways were jammed up. Replaced coolant pump hoses and that's working well now. Still trying to figure out how to properly adjust the lead screw things as the work table is a bit uneven with its travel while...