The Clifford supplied gasket material for the header flanges and the intake/exhaust manifold are made out of the same (white/rubberized) material. This material is also about 3 times thicker than the gaskets I removed. I soaked the new gaskets for 45 minutes in warm water prior to install as per the instructions from Clifford. The flange gaskets got very brittle after only 100-200 miles of driving. I am still getting a slight whiff of burning rubber from that gasket material. The Clifford Rep says this is the 1st that they have heard of this type of failure. One thing that may have contributed to the failure of the collector gasket is the torquing/twisting in that area from the engine movement whereas the intake/exhaust gasket is not subjected to those stresses. I think I will spend the extra $$$ for copper for added insurance.
