I've never had cork china rail gaskets dry out, get saturated and leak, because I've never used them. All I've ever used is an appropriately sized bead of RTV on the end rails, and have never had a leak in that location. Of course, I've only been messing with these cars for about 25 years, so there are folks with a ton more experience around here than me.
Right! Anyone whose ever cruised rows at a junkyard knows, factory cork gaskets fail. That's why you see heavy, greasy, oily buildup on timing covers, oil pans and blocks. The original cork failed over time and seeped oil all over the engine.
I will say cork is a good gasket, for a time. It conforms great to uneven surfaces and can even fill in small scratches and holes as it's tightened down. ....but so does RTV and it will not fail. I have a cork valve cover gasket on Vixen, because I could not get that new fangled silicone gasket everybody raves about to seal, no matter what I did, so I put cork on it and bam it stopped leaking. But I know sooner or later, the cork will fail and it will leak, so I keep a lookout on it.
