Buy headers. Stock exhaust manifold on the TJ, although similar in design to headers, is notorious for falling apart. Why do it to yourself again? I put plain black headers on ... Hedman maybe, Borla ... I can't remember. It's a PIA and took me 5 hours but it isn't difficult. I drive my Jeep, not show it, so I saved $ and went plain black. For the intake, I cut the tube from the air filter box, put a K&N on it, free breathing now.