[swcash]

Ditto on the Indian Head or the Permatex Soft. I always go with the brass plugs. Never had one fail. I am getting paranoid about silicone, I find way too much of it EVERYWHERE, oil pickup screens and cooling systems. Blocks the radiator too.
The only place I use it is to fill a gap like in the corners of the intake or oil pan gaskets. Then I make sure everything is squeeky clean and then use it sparingly.
Squido