I don't know if there's such a thing as high temp primer but you might want to look into it. We sanded and sprayed my brother's Heddman/Chikara header with high temp paint knowing that the black "storage paint" would have flaked off and burnt away anyway. Unfortunately, the paint started to peel and flake away at the bends (the parts that get the hottest), especially on the primaries. It could have been that we didn't let it cure for long enough. We only waited a couple days before installing. I hear of some people putting their stuff in an oven to cure. Good luck.