Just my opinion alert.
I personally swear by this stuff: https://www.amazon.com/Permatex-99070-Right-Stuff-Gasket/dp/B000HBM6PE
If you need something to not leak, this is the stuff to use. I have heard that it is kind of a pain to clean off if you need to take it apart, so I typically only use on things that I plan to not have to take apart for a long time (or hopefully ever)
For the intake manifold gaskets, i know felpro says to put the gasket on dry, but due to the corrosion issues I have seen, I will smear a thin layer of this stuff around the coolant ports on both the heads and the intake manifold. The intake ports I leave dry. I also put a small bead of it in the corner where the block, head, and manifold come togerher. Mostly because the GM engines in my experience tend to develop an oil leak there. This has been my method and has worked well for me. Ive done it on two 3.8L V6 (incl my reatta), a 3.1L V6, and a 5.7L V8, which all have a pretty similar design. All of them had a good bit of corrosion at those ports. Prev owners had left old antifreeze in them for a long time unfortunately.
I think if there was no corrosion I would consider putting the gaskets on completely dry, but maybe would put sealant anyway to help prevent corrosion. I don't know. However @2seater your method of filling the pitting with epoxy is very interesting to me. I might have to try that on the next one. Out of curiosity, where did you get the idea to do that?