Gaskets are sealant.. Like mentiond above, a skim coat on a pitted surface or a dab on a "T" joint where three peices meet is all that is needed.. I'm a huge fan of Motorcraft diesel silicone, available at the Ford dealer in a calking gun tube.. Use sparringly, it has an epoxy like property.. I cant help but laugh when I see thermostats glued on with two tubes of orange or blue silicone.. Totally un necessary, ugly and counter productive. If it squeezes out the outside, it does the same on the inside, clogging passages and even oil pump screens when used on the pan..