[Brian in Oregon]

I've run studs and brass nuts on various exhaust manifolds. Also use spring lockwashers instead of split lockwashers, as they don't dig into the nut.

Sometimes brass lockwashers aren't the best, though. Some headers can require a fair amount of torque to properly seal, even with thicker "header" gaskets. You can strip out the brass nuts. In this case, I use regular nuts with anti-seize, and once a year remove each nut and retorque it to ensure it won't stick.