I don't know why cork still exists. Cork gaskets cut easily if overtorqued, they age rapidly, and the seep oil. Rubberized cork, felt, and neoprene gaskets are worlds better than cork. Any place the mating surfaces are flat (eg. thermostat housings) it is better to use no gasket and put a little silicone in there. I still use gaskets, though, because they clean up easier. I use Hylomar HPF to dress gaskets. It's extremely tacky, so it will hold the gasket in place, but it never hardens for easy disassembly and cleanup.