Originally posted by BrentA
im sure the wrap does help since headers are meant to keep the exhaust gases cooler, for more ponies, and if the wrap cools the headers even more, then im sure they would help, plus if they are rusty im sure it would look better then rust
A header frees up power by having larger diameter piping, reducing backpressure, not by cooling the exhaust.
The header wrap keeps more of the exhaust heat from soaking into the engine bay, so you will have lower engine bay temperatures, this is beneficiial because your intake piping will be cooler, and so your intake air charge will be cooler.