How is Doug's Black Coating???

Getting ready to pull the trigger on D450's for my 64 Dart GT build, just wandering if their coating will hold up, or should I buy them raw and have a known good coating put on them?
Thanks

Having the inside of the tubes coated after chemically preparing them is hard to do at home. Painting the outside of the headers is easy to do.

I have had excellent results using the VHT brand of high temperature paint on my entire exhaust system. It's very durable, easy to use and relatively inexpensive.