I used PB on my 1987 exhaust manifold and every bolt came off with no problem with just my socket set (at 270,000 miles). You may not get so lucky, but you never know.

Lee

1987 Raider 2.6L Auto -- rebuilt, by hand, by me -- Bouncy Seat/LSD/Aisin Hubs -- CB/Whip Antenna --Jensen Stereo -- Fire extinguisher .