streetxj
NAXJA Forum User
- Location
- Pembroke Pines, FL
A couple of weeks ago my dad and I installed a gibson stainless header on my 1996 Jeep XJ 4.0. I bought it new for 285 bucks on ebay. The welds look nice and not sloppy. The overall quality of the header looks very good and it was made in the USA (not Chinese). At idle and cruising under 2000 rpms I can hear the individual cylinders a bit more (has more of a v8-like burble sound) and the exhaust has a smoother and deeper tone when it is revved. It feels like there is more torque throughout the rpm range and the engine is definitely more responsive. The biggest difference is felt when you give the engine a good amount of throttle (1/2 to wide open throttle). It definitely accelerates easier. The difference is similar to the intake manifold upgrade. I eliminated the thermotec heat wrap from underneath since it was falling apart and calcifying the bottom portion of the intake manifold. I've also noticed that my engine runs a bit cooler now. That could be from eliminating the heat wrap or the improved exhaust gas scavenging resulting in lower combustion chamber temps. My stock header did not have any cracks whatsoever, so the performance improvement is not from installing a header with no cracks. The header alone might not give a justifiable difference, but it is one of those mods that work best if you already have a high flow exhaust and a high flow intake system, bigger throttle body and newer style intake manifold. I'm also running bosch 703 injectors and a few ignition goodies.
