I don't have any personal experience, but the guy I bought my Sidekick from had a header on the other Sidekick he built...16v motor...His opinion was that the header was not worth the headache. He said the performance increase was minimal, and keeping everything away from the heat was a challenge. The heat from the header melted his clutch cable on 2 seperate occasions while out crawling in the mountains in Colorado...That being said, I may end up buying a header also...my manifold is cracked and I have had no luck finding a new replacement, so a header may end up being the only option for a replacement, unless I get lucky and find a used manifold.
