3SX Stainless Steel NA Long Tube Headers
91-99 3000GT DOHC & 91-96 Stealth DOHC

* * * MADE IN THE USA * * *

3SX has partnered with Kooks Custom Headers, located right here in North Carolina, to finally design the once-and-for-all ultimate long tube headers for the DOHC 24-valve Non-Turbo 3000GT and Stealth!!!! We did it the right way and started with a WHOLE CAR! Kooks used their state of the art header design equipment to literally scan the engine bay and attachments so they knew exactly the space they were working with.

THESE are what you have been needing for your non-turbo 3000GT/Stealth! 3SX developed custom LONG TUBE HEADERS for the non-turbo 3000GT and Stealth! Featuring 23" individual runners for each cylinder, these are designed to strengthen the car in the mid range and top-end. And they DO! The car pulls stronger and longer when pushed hard. We also included a flex-section to maintain flexibility once installed and mated to the rest of the exhaust system.

DYNO PROVEN POWER! We went above and beyond any other supplier in the 3S market and dyno tested these headers to PROVE you are gaining 10 HP at the wheels over 6000 rpm! Check out our complete 3SX NA Exhaust Dyno Testing page for more details.

The system was designed to meet our specifications and have proper clearances and the best fitment of ANY non-turbo exhaust component on the market! A mockup was designed and tacked into place to confirm fitment and clearances, then the final product was cut and mandrel bent by computer-controlled equipment. Elaborate jigs were then made to ensure that EVERY set of welded-by-American-hands 3SX Long Tube Headers are exactly the same and meet both 3SX's and Kooks exacting standards!

Our new NA Long Tube Headers are made with US T304 Stainless Steel and carry a limited lifetime warranty to the original purchaser!

1-5/8" runners

2" bank collectors

2.5" outlet pipe/flange

Factory restrictive 2" pipe

Smooth and flow-friendly welds at the heads.

Slip-fit with clamp junction between the front and rear banks.

Installation Tips/Pointers:
REAR: You will need to remove driver half-shaft and rear engine bracket - the piece between the mount and the block. The rear bracket should go back in WITH rear header piece.
FRONT: You will need to remove the front engine bracket from the block (the bracket between the mount and block), separate the alternator bracket from engine (remove belt) to get the old manifold out and the new header in, and bend oil dip stick over to driver side a little to clear the pipes.
GENERAL: We recommend getting the manifold nuts on first, loosely holding the front and rear banks to the heads, but leave them a couple threads loose to allow a little play in the pipes. Then slip the front and rear banks together. Then tighten the manifolds to the heads, then final tighten the clamp where the front and rear banks meet. This will allow everything to get the best seal and simplify aligning the pipes.

As always, we recommend NEW motor mounts to go with your new headers. Old worn motor mounts will cause the flex-section to prematurely fail and lead to exhaust leaks. We offer the 3SX Custom Polyurethane Motor Mounts and the 3SX Custom OEM-Replacement Rubber Motor Mounts.


FED vs CALI Spec: The headers are set up for direct use on the FED-spec cars (91-93, some 94-95) as the O2 bung is located at the back where the FED-spec single-sensor cars have the O2 Sensor. For installation on a CALI-spec car, you will need to have bungs welded onto the pipes and probably extend the wiring for the sensors to reach further down the exhaust depending on where you choose to install them. Obviously, the header kit installed on a CALI-spec car will eliminate the two pre-cats as well, so it could possibly trigger the check engine light. The O2 Sensor Spacers should remedy that situation.
NOTE: This modification may not pass local emissions or inspection laws - check your local ordinances.


NOTE: This is a LONG tube header kit - it replaces the manifolds AND downpipe, going between the heads and cat/racepipe.


NOTE: These will ONLY fit the DOHC Non-Turbo 3000GT and Stealth:
1991-1996 Mitsubishi 3000GT Base
1991-1999 Mitsubishi 3000GT SL
1995-1996 Mitsubishi 3000GT Spyder SL
1991-1993 Dodge Stealth ES
1991-1996 Dodge Stealth RT


Limited Time Combo Special!!
For a limited time, get a great deal on an NA exhaust upgrade!
Get the 3SX Headers and a 3SX/Kooks High-Flow Cat and save $50 on the combo!!
Get the 3SX Headers and a 3SX Race Pipe and save $10 on the combo!
These discounted prices are reflected when you add the combos to cart below.


The gasket between the headers and cat IS included.
Two of these gaskets ARE included if you include the cat or race pipe.

Manifold gaskets are NOT included with the headers.
GASKET-8115 goes between the Heads and Headers - Order QTY x 2 for both sides.


Picture of 3SX NA Long Tube Headers SS USA - DOHC Headers
3SX NA Long Tube Headers SS USA - DOHC Headers
Picture of 3SX NA Long Tube Headers SS USA - DOHC + Hi-Flow Cat
3SX NA Long Tube Headers SS USA - DOHC + Hi-Flow Cat
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