I've never had a problem with dry gaskets. If you've got an exhaust
problem the sealant isn't going to help much. Plus, if you have to
replace one, and the gaskets have slots instead of holes for the bolts,
replacing one that did not have sealant is easy, just loosen up the
bolts enought to pull the old gasket out and slide the new one in. If
you have sealant you have to remove the manifold and clean the
surfaces. We all know how much fun it is handleing those heavy
manifolds, while trying to get the bolts started, while trying not to
distroy the new gasket in the process.