I use what ever non-hardening is around for the timing chain cover since I usally only buy the better brand name stuff. Now for the transmission pan gasket I never used any RTV or sealant as there is always that fear some could end up on the inside & make it's way into the circuits. Used to have a nice size can of good ol' GAA (Grease, Automotive Artillery) & used it to help keep the gasket in place as everything is put back together. Never had a pan leak.
