Chuck. Unless that’s high heat powder coating, it may prove to be a problem when the exhaust temperature heat is put to it. And if you have any on the inside of the headers, then any scavenging taking place during the overlap cycle can be pulling this into the cylinders. I’ve seen what the standard powder coating does to cylinder walls and it’s not pretty; the heat cooked powder coat as it comes loose creates a lot of damage to both the cylinder walls and the pistons. If this is a metalized powder coating, then the temperature capability is likely higher but check out what you currently have before putting these on a good engine and testing.