Compression test results and plug color question.

Be careful if you have power brakes before shutting it down.

Check port alignment to head.
Disconnect the pcv, plug it and drive it cruising, no wot and then check the plugs again...who knows.

Everyone else have covered most things to check. Shortest wire of a set of crappy high resistance plug wires perhaps, lol. Maybe not, maybe you have good wires...maybe you fouled the plugs at one time, short of that one and they never cleaned up. Lol