Originally Posted by Mopar Mitch
Although I'm not certain what brand Superformance uses, they are probably the same Viton rear seal that the Fel-Pro is... they are all sourced from major "seal" manufacturers. Changing the retainer is most helpful.... regardless of the seal source.

I'm a former long-time aftermarket engineer from Fel-Pro.
iagree but I'm not a long time gasket engineer shruggy
I buy those seals by the dozens so I don't run out on the weekend or at night, no leaks in a longtime on both knurled or smooth cranks up

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)