one time i made a set of studs for a 360. it helps keep the gasket on. and looks cool. and a to long bolt doesnt bottom out. and taper the top of the stud so you dont cross thread the nut.
I thought most are studs 1/4-20 on head side, 1/4-28 on nut side. Perhaps I am thinking of my 65 Newport (383). Ace Hardware, or you can get purty chrome studs & nuts on ebay.