Well you can get the "BEST" gasket or felpro, (probably the best 2 options) but they will all be cork as far as I know. I don't believe any one is making the reusable silicone gaskets. I agree that would actually be the best idea, but the reality is, you can't get what someone ain't makin'. I have never really understood the recent/modern use of cork, it doesn't really even work that well. Back when these trucks were created, it was fine to build a machine that leaked oil all time. Now though, it isn't OK. And there are much better alternatives out there. I finally ended up using lots of permatex. I don't like it, and generally like to use never-seize on most gaskets. But these (all of the engine gaskets for that matter) don't seem to respond well to that method.
