I've never found a paint that will last for very long on headers. Even the apply at home thermal coating I tried only lasted a few years before it eventually cooked off. I've always been very diligent about prep work too. Tried sandblasting, bead blasting, cleaning with alcohol, cleaning with lacquer thinner, cleaning with acetone. I've tried VHT, BBQ, and other high temp paints. I'll also add that my engines have tended to be at the higher end of the compression spectrum and tend to produce some very high exhaust temps. Whether that is a factor or not, I'm not sure.