gasket sealer

I go by either the instructions or gut feel if there are none. (or past experience.)

Using the classic Chevy V8 as an example - head gaskets are dry. Intake gaskets - toss the end seals and use silicone. water pump to block gaskets are fine dry, but I've had less leaks by just siliconing the timing cover on.

I guess it depends - some gaskets are very picky (head gaskets) and some just aren't that picky... I know guys who silicone valve cover gaskets on and guys who use cork and both are happy...

Ray (who would like to see what would happen if you used silicone on head gaskets... on someone else's engine.)

I've never Permatex'd and regretted it in auto or marine.

When I build race engines I use a thin layer of orange Permatex on all paper gaskets that need to seal fluid, except for the head gasket. I dab it on and massage it in to both sides of the paper gasket by hand, making sure that there is no excess to squeeze out. I try not to use the thick cork type gaskets for oil pans, but I do use them when I have a pressed steel pan to put on. I prefer cast (or billet) aluminium oil pans over steel. I put head gaskets on dry but I have used a product called Super Seal on head gaskets around the water passages to get through a weekend. I glue cork or rubber valve cover gaskets to the vave cover using Super Seal, and leave the head side dry - they are good for a season at least of constant valve checks and adjustments. I like Super Seal, it's rather amazing stuff - I put some on a diff housing to seal up a hole where part of a spider gear sought (and gained) freedom, and that repair has lasted over ten years...

Brian