Headers can get to 800degF without much trouble.... was thinking about using the metal tape we stock(good for 600 degrees) to secure the header wrap on the pipe. ...
This will definitely work for that application, however, it won't cut down on the heat transferred back into the coolant and oil from the headers where they pass close to radiators.You can cut and place this high heat tape on the inside of your plastic parts to protect up to 2000 degrees. ...
http://www.thermotec.com/dezzy, does thermotec have a website or phone# . i might change wraps.
btw thanks for posting pics, job looks great