When we build King Of The Hammers, Supra Drag Race Competition, and Baja 1,000 Desert Racing transmissions, we use Permatex Ultra Gray Silicone.
Permatex Ultra Gray RTV Silicone is Made in the USA for the professional mechanic. Designed for high torque and load applications and exceeds import manufacturer's performance requirements with outstanding oil resistance. It is non-corrosive and can sustain a high temperature rating of 625° F.
Tube contains 3.5 ounces / 99 grams. Made in Solon, Ohio.
Terms:
RTV = Room-temperature vulcanizing, meaning that at room temperature this silicone will cure or "set" into its final rigid shape to seal two components together.
FIPG = Form-in-place gasket, meaning it is a substitute for a traditional die-cut gasket that is initially soft and malleable before it cures.