Whats the best sealant to use on exhaust studs in a BB head? I don't want them to leak, and also don't want them to back out next time I have to fool with the exhaust manifold. It's in a motorhome,and will probably crack this one sometime in the future, like it did the last one. I plan on using anti seize on the threads on the manifold end of the studs. Any tips and ideas appreciated.