What exactly is a header? A header is a modification you make that replaces the exhaust manifolds with high flowing components that increase the rate at which exhaust leaves the combustion chamber. This not only improves sound quality, but it is really meant to help increase horsepower. With Wranglers, you have three options you have shorty headers, long tube headers, and tuned length headers.
Shorty: Shorty headers are the most common and the user-friendliest type of header on the market for Jeeps. This is because they simply bolt in place of the stock manifolds with no mods to the factory exhaust being required. They also will not interfere with ground clearance, which does come into play with other header types.
Long Headers: Long tube headers bolt to the cylinder head just like a shorty would. Though, the tubes that run off the header are longer and will require the exhaust to be relocated. This means either the installer will need to perform some modifications to the exhaust or will have to call an exhaust shop to do the job. With that said, long tube headers may not always interfere with ground clearance but they can, depending on the part you are working with.
Tuned-Length Headers: The last type of headers will combine the best of both worlds. They use long tubes to help increase power but bundle them up into a compact package so that the user can get them in place of the stock manifolds like a shorty header.