My dad was watching Trucks! the other day, and he mentioned that as they were installing the exhaust, he used a sealent where the pipes slid together in conjunction with the clamps. There are a few spots on my x pipe that are leaking (yes I have taken it apart 3 times, only reducing the number of leaks, breaking one clamp in the process of tightening them) and had considered using some sealent. The only stuff I was able to find was some 700 degree gasket sealer, but was not sure if there was something more specific?