if you go for dome nuts, make sure that the thread on the stud does not contact with the dome inside when torqued up, easy to get this wrong as the gaskets will compress when the nuts are tihjtened and lead to the stud tightening against the dome inner, givine the feeling that its fitted correctly when it isnt. A simpler option is to use connector nuts so its not a problem how much thread is exposed https://www.screwfix.com/p/easyfix-a2-stainless-steel-threaded-rod-connecting-nuts-m6-10-pack/4720g [Edited to fix the broken link: GrahamM - Moderator]
The phrase Sharp was possibly looking for is 'galvanic corrosion' where you have 2 dissimilar metals (Aluminium alloy of the cylinder head and the mild steels of the studs.
Leave the studs alone, count your blessings, and buy a lottery ticket