Conversion Headers

for the

GM Generation III & IV Small Block V8

in

XJ & MJ Jeeps

The GM LS V8 engines are the prime engine for the Cherokee Jeeps. Designing exhaust headers to fit just right into the Cherokee & Comanche Jeeps was tough, but the result is spot on.

Product & Features

Block_LSXJ3C


About the Headers 

The header starts with a generous, 3/8" thick manifold flange. A patented port-seal surface is face ground at the mounting face of the engine head such that they can be used without a gasket (see installation notes below for more information). Headers feature 1-1/2" primary tubes with a 2-1/2" three-bolt style collector.

In the box

Included are Left and Right headers, header-to-head bolts along with instructions. Gaskets and collector bolts are not included.

Coated or Natural Steel 

The basic header is offered in natural steel, which the customer can optionally have finished in a variety of hi-temp enamels or other finishes that will offer rust protection and good appearance.

The best thermal and corrosion protection for your headers is our Aluminized Ceramic Coating. This finish offers the added benefit of lower under-hood temperatures and the highest level of protection to the header.

Applications & Compatibility

Engines 

These headers are compatible with Gen III & IV GM V8 engines, this includes both the LS and Vortec engines starting with the LS1 in ’97. Truck Vortec series started in 1999. If your exhaust ports are paired in the center these will NOT fit and you likely have a Gen I or II engine needing these headers. While the headers themselves will fit a Vortec style engine with the tall truck intake, the intake and brackets will not fit in your Cherokee without substantial modifications over multiple areas. See below for links to valuable information.

Jeeps 

These headers are designed specifically for conversions in the XJ/MJ chassis.

Related Products

EGR Block-Off Plug

For early cable throttle engines that were originally equipped with EGR (Exhaust Gas Recirculation). The following kit is recommended to block that opening in the intake manifold. Legality of removing the EGR is determined by your local emissions requirements and requires electrical modifications to the control circuits for proper operations without it. Consult the article linked below for more emissions information.

Block_12558346

Novak Engine Mounts for Gen III & IV

Block_MMXJ3

Installation Requirements

Recommended installation to the engine is high temperature RTV such as Ultra Black® without a gasket. We have found this works exceptionally well. Some have used the original equipment type MLS (multi-layer steel) gaskets with good success. Collector gaskets and bolts are not included with the headers. We recommend using solid copper gaskets to avoid blowouts at that joint. Instructions are provided with the headers.

The short, block-hugging design allows the installer to have the exhaust routed in one of the following three popular ways: 

  • One circuit under the oil pan, just in front of the sump merging into the opposite circuit which is typically run rearward on the side of the Jeep opposite that of the drop of its transfer case.
  • As above, but under the bellhousing slope.
  • As above, but behind the transfer case. Then, the exhaust tailpipe can exit the Jeep on either the driver's or passenger's side.

Also See