Phil's stuck spark plug

[John Larson]

Years of P car wrenching have led me to conclude that a good soaking
with a quality penetrating oil (Kroil, Blast Off, PB Blaster, etc.), and
getting the engine good and hot before attempting to remove the plug
work about as well as can be expected. I'm sure there are good products
like those I listed in the UK as well. You should plan on reconditioning
the plug hole, either with a cleanout tap (or thread chaser) or an
insert like a helicoil or timesert. WD 40 and liquid wrench are probably
a waste of time. Good luck, John