727 Transmission leaking

Okay, I`ve replaced all of the gaskets except for the front pump seal. It looks all good but the pan gasket still leaks! This is the 3rd gasket on it. First rubber gasket was replaced with rubber, then the rubber was replaced with cork, then the cork was replaced with rubber with the addition of silicone. The last gasket swap was accompanied by a thorough cleaning and careful straightening of the pan. I`m at wits end with this thing. The only other thing I can think of is to try a new gasket that Mopar makes now that has a steel center with rubber coating. Anybody used one? What`s better cork, rubber, steel/rubber, silicone?