I don't want to offend any one. But I think brass nuts are terrible. They gall and over many years of factory maintainence & auto repair I have had poor luck with brass nuts.. On marine application & food processing I got used to stainless steel nuts - my current chhoice on exahust. I never had one problem using stainless fasteners.
I thought I would share another trick. I stumbled on ace hardware furnace cement - it seems to have a better adhesive then other furnace cements. I use a very thin (almost transparent skim coat on both sides of the gaskets. It helps to make a better seal - I have saved some old manifolds by using slightly more to fill imperfections (such as pitted surfaces).
My 2 bits only worth 2 b its but then 2 bits are 2 bits . :-) Mr bill