If your flanges are truly flat, you can use a 1/4" thick bead of 100% GE silicone about 3/4" outboard of the port. Bolt on the header and forget it. The silicone extrudes down to near

zero thickness in service. It has never leaked. It is not exposed to pressure even with a high flow muffler in place. The high velocity at the port means low pressure. If the seal fails, air will leak into the exhaust system and make a popping sound on closed throttle.

 

Works great. Lasts until you remove the headers again. Cheap.

 

Lynn E. Hanover

 

Lynn,

Someone told me that Silicone destroys 02 sensors - is that true?

George ( down under)