Headers and paint- - - - -that's a lost cause! Powder coating, maybe, but I've never seen any kind of paint, including the "high temperature header paint" that will last more than a few minutes, or the first hard uphill pull, whichever comes first. The temperature sensors on our dyno headers would indicate exhaust port temps of 2,000 degrees or so on a full-throttle run under load. No paint in the world is going to survive temps like that.
Late ignition timing and/or a lean mixture will cause cast iron exhaust manifolds to run red hot. Headers will get hot enough to melt spark plug wires and blow out gaskets. After over 50 years of building race engines, somebody would have to chase me a long way to try to GIVE me a set of headers!
Jerry
