Folks, finsihing up the GPs on a 235K mile 606. Did the easy ones before 3-4-5, now doing 1-2-6. 2-6 are "unbolted" but wont come out due to swelled tips and carbon, I guess.

Have soaked them down pretty good with PB blaster. The trick I used on #`1, continuing to "unscrew" while applying outward pressure with a screwdriver, isnt budging #2 or # 6.

Cranked it over a few times to blow debris out #1 ( reamed the hole) before I put the new GP in. The craking did nothing to move 2 or 6. Now I am thinking of firing the engine up and see if the combustion blows these two plugs out. But I prefer not to put a hole in the fender ( although 6 is right behind the oil filter can).

Anyone BTDT and can offer some tips?

If not firing the enigne ( which puckers me), I can try and cut a nut in half, collar the GP and see if it can be further unscrewed. Have already broken the inner from outer on #6 and dont really want to break the plug while its in the head.