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Conversion Headers

for the

GM Generation III & IV Small Block V8

in

XJ & MJ Jeeps

LS Vortec Headers for XJ MJ Cheroke Comanche Jeeps
LSXJ3
LSXJ3C

Kit contents:

  • Headers, left & right
  • Header flange bolts
  • Collector flange rings
  • Collector flanges

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.

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.

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.

Compatible 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 1997. 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 manifold and brackets will not fit in your Cherokee without using the lower LS intake and front accessories. See below for links to valuable information.

Compatible Jeeps

These headers are designed specifically for conversions in the XJ / MJ chassis only. They may work in other installation situations, as determined by the installer, but for all other known Jeep LS installs, we recommend these headers.

GM Vortec LS Engine Header for XJ Cherokee, driver's side
The driver's side header on an engine that's headed for its home in a Cherokee.
GM Vortec LS Engine Header for XJ Cherokee, passenger's side
The passenger side of our header kit is more swept back, to put the primary pipe in the provided nook between the unibody and the firewall.
4L80E headers inteference
Warning on 4L80E installations in XJ Jeeps:
the extended flange of the transmission case will interfere somewhat with the flange of the Novak headers. While we think the 4L80 is a terrific transmission, it's overkill for just about every Cherokee out there - a 4L60 is usually a better option.

Related Products


Mounts for LS Vortec Engines in XJ MJ Jeeps

Kit MMXJ3, engine mounts, GM Gen III engines into XJ Cherokees & MJ Comanches

We nailed the installation location, strength and clearances with our LS Vortec XJ / MJ engine mounts kit. Learn more about them.

MMXJ3
Exhaust collector gaskets in copper

Gaskets, collector, copper, 2.5” ID, pair

These are our preferred collector flange sealing gasket in durable and conforming copper that will outlast the fiber gasket options.

7176C
Radiator for GM LS Vortec engines in XJ MJ Jeeps

Radiators for GM LS to Cherokee Conversions

Cooling a powerful engine in a Jeep takes serious radiator and fan combinations. Learn more about ours, here.

Pilot bushings for Jeeps

Pilot Bushings for your Jeeps

Many engine conversions will be up against manual transmissions. We offer pilot bushings for just about all of the combinations that we've encoutered over the years. See them here.


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.
Jeep XJ exhaust routing GM V8
This is one of our prefered exhaust routing jobs on an XJ. It's tight, but it works great.
Jeep XJ exhaust routing GM V8
A macro shot of the above exhaust routing. The 2-into-1 muffler helped make this a clean job. Note that not all emissions jurisdictions may allow for the catalytic converters to be this far from the headers. Do your research.

Also See