Well, there's a new one; I haven't heard of anyone on here cutting their own manifold gaskets? Robs are very affordable if that's the way you want to go. I'm on the side that believes the corks suck, and are only good short term(1 day at the races). And yes, I used the 5-5-10 sequence. Both times that I've tried the corks, I've had the same results. When removed, the very thin smooshed out cork into the port was cooked and getting ready to let go. It would be sucked right in to the valve if that occurred. No worry about that happening w/ the OEM metal gasket. And also to mention; the smooshed out cork is interrupting the air flow a bit. My $.02