huh. i never thought of that, i always just used spray silicone. there was a guy i worked with that absolutely insisted, like swore up and down to the point that he wouldn't put one together without using pam, yes, pam cooking spray, on the gaskets.
i agree matching the gaskets to the ones you took off, but only to a point. if you don't know the history of the carb and somebody else was in there and knocked the wrong gaskets in then you're just repeating the bad work. trust, but verify if you're unsure.