Steeda's instructions for installing their underdrive pulleys includes this step:
Hardening
http://www.permatex.com/products/au.../auto_Permatex_Form-A-Gasket_No_1_Sealant.htm
Non-hardening
http://www.permatex.com/products/au.../auto_Permatex_Form-A-Gasket_No_2_Sealant.htm
Autozone had two kinds of Permatex Gasket Sealant. Which one should I use?Apply a dab of high temperature silicone sealer (gasket maker) to the keyway slot on the underdrive crankshaft balancer pulley. Line up the keyway and install the pulley.
Hardening
http://www.permatex.com/products/au.../auto_Permatex_Form-A-Gasket_No_1_Sealant.htm
Non-hardening
http://www.permatex.com/products/au.../auto_Permatex_Form-A-Gasket_No_2_Sealant.htm


