I used Super Weatherstrip Adhesive on the gaskets just to keep them in place because the engine was still in the car when I did it. It has never leaked.
If the engine is still on a stand, you won't need any sealer, as long as your surfaces are clean & flat. Having pan studs & nuts is much better than bolts too.
Cork? Or cork rubber? Always prudent to make sure that your pan rails are flat, length and side to side. I usually spray both sides with a little Permatex High Tack.
Description says that it's a cork rubber gasket. Your choice, dry or sealer. I must ad that I have small blocks, not big block , have different sealing issues. Don't overtighten them. I usually watch the squish area, tighten evenly till they just start to bulge at the fastener area. At least that's my method.
Good luck!