Compression test was good, all within 5 PSI of eachother (165-170 psi holding the pedal down. No clue if the throttle blade actually opened). The culprit appears to have been the fairly bad carbon buildup - though several of the intake manifold bolts were essentially finger tight, so maybe there was a boost/vacuum leak, too.
It is interesting that this could cause a consistent misfire on a single cylinder.
