I'm going to postulate here and suggest that you're thinking that you want to go back to a double wall header system to reduce the heat at the front of the engine. Quite often the inner pipe rots out and you're back to a single walled pipe. You could consider sending out your DG pipe to
Jet-Hot ceramic Coating
and have them ceramic coat the header. Appearance remains the same and header temps will plummet. An alternative you might like to try is
Eastwood's internal ceramic coating
. The inside of the header would have to be cleaned out - sandblasting maybe?
Just some thoughts.