jcatnite
Jedi Knight
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Red locktite is a retaining compound. It isn't a sealant at all. In fact the red locktite might have swelled a bit as it set up forcing the plugs away from the sealing surface a bit. The black permatex is a sealant and won't harden. I think you are better off. The interference fit between the plug and the block is really what causes the plugs to seal up. The black permatex is just insurance.
JC
JC