I've used the Mr. Gasket 3415 header studs on a few engines now with good results. Both steel and aluminum heads.

They have two thread sizes on the stud with a smaller 5/16 thread sticking out to make header installation and nut clearance much easier.
I usually buy better grade 8 nuts to replace the ones included with the studs.
I don't believe they are currently being made/sold new but they do show up occasionally on e-bay.