Just drove it again, and when I first left and went over 3000, it felt like a switch this time. Interesting.
Good point though, it makes sense. I wonder if the O2 sensor actually has anything to do with it.
It really feels like cam timing, but the vacuum is still a little on the low side. And of course it's jumping around like crazy. The really odd part is that it ran pretty much exactly the same prior to swapping the head and cam.
Basically, this is where I am...
-get an adjustable cam gear and advance the timing a little
-replace the trashed engine mounts
-adjust the valve that was a little tighter than the rest (just ordered the correct size shim)
I've pretty much ruled out anything and everything else. Timing, vacuum leak, fuel pressure, injectors, plugs, cap, rotor, wires, power stage, TPS, MAF (I suppose it could be failing, but typically that'll throw a code, no?), etc. I haven't swapped the fuel system relay yet, but if the pumps are working and I have good fuel pressure, I don't think it's a problem.
The only other thing I can think Same goes for the radio suppression relay.