63 Dodge Dart, now let me see;)

Good morning! :thumbsup: I need to pull my intake/exhaust back off to seal the studs BETTER (permatex didn't work), someone said the Remflex gasket is not re-usable? I do have one coming. But since it hasn't been ran, is it still not re-usable?
If Permatex didn't seal, something's wrong. What product did you use?