$#@# leaking trans pan.

Forget either type of floppy gasket (cork composite or rubber). Forget trying to seal a warped old pan.

A nice new heavy-duty pan with unwarped rails can be had from the dealer under p/n 52118 779AB, and it even includes a doughnut magnet to catch metallic shavings. While you are at the Chrysler dealer, get the really nice double-seal, reusable rigid pan gasket p/n 4295 875AC. Use new correct 5/16"-18 × 5/8" bolts with captive washer, p/n 4723 548.

It will never leak again.