How to safely remove bumper?

[80BELLA]

I'm in the process of removing rotted rear floor in 1980 Caravelle and want to remove the belly pan, but the bumper has me stumped. The 4 pan-head screws will not budge. I soaked overnight in WD-40, tried percussive maintenance, even went out and purchased the awful-smelling JB Blaster. NOTHING. Since the JB Blaster says it is extremely flammable, I am wondering what the next safe step is? If I attempt to drill them out will that get hot enough to be a problem? Sorry for such a basic question - just want to be safe. Thank you!

[rugjenkins]

Drill it out- it won't burst into flame.

[blickcd]

This is an old thread but I got those screws out using brake fluid as the solvent, and a manual impact driver, the type you whack with a hammer.

It took a week of soaking, scrubbing threads with a small wire brush, and sometimes heating with a torch.

In hindsight drilling would have been much faster but those look like tough screws to find.

[airdreamers]

I would drill out the screws and then if the hole is not clean re drill with next size up drill bit and then tap. Now your good to go all new. Lube up before assembly, this will prolong the life of the connection.