Header Wrap, what do you like

In reality the wrap is to keep the heat in and the velocity high adding HP, do you need the xtra couple HP on the street?

I just did a cam change, and took the nasty dam stuff off, "what was left of it"! Got tired of getting fiberglass in my arms every time I had to work on it. Still don't have the dam stuff completely out of my garage yet. Guess I`m going to have to take the hose to it or mop it out.
Fisrt things first/ still have to reset the valves.
I did have my headers coated w/ 2000 degree something or other, satin black, look pretty fair, for used headers to start with.