I wouldn't ever use silicone on the gasket, but I wouldn't use Permatex either. The best stuff is GM gasket sealer that you can buy at the GM dealership. Not only does it seal well, but you can get it loose when you need to and the gasket almost always just peals off of the part or the block with no trouble. But, silicone is the best thing to use on the screws. Regular gasket sealer will not work on the screws.
