How to Install Gibson 1-5/8 in. Performance Headers - Ceramic Coated on your Silverado

WHEN THESE INSTRUCTIONS ARE FOLLOWED PRECISELY, YOU WILL FIND THE INSTALLATION OF YOUR EXHAUST SYSTEM TO BE RELITIVELY SIMPLE. WE CANNOT OVER EMPHASIZE THE IMPORTANCE OF ADHERING STRICTLY TO THIS PROVEN APPROACH, AS IT WILL VIRTUALLY ELIMINATE ANY DIFFICULTIES, WHICH YOU MIGHT OTHERWISE ENCOUNTER.

NOTE: INSTALLATION OF HEADERS ON VEHICLES WITH CATALYTIC CONVERTERS AND/OR OTHER EMISSION CONTROL EQUIPMENT MUST BE ACCOMPLISHED IN ACCORDANCE WITH ALL GOVERNMENT REGULATIONS PERTAINING TO SUCH EMISSIONS STANDARDS.

WARNING: MAKE CERTAIN YOU HAVE ENOUGH CLEARANCE AROUND BRAKE, FUEL, AND ELECTRICAL LINES, ETC. IN SOME CASES, IT MAY BE NECESSARY TO RELOCATE ITEMS WHICH MIGHT BE ADVERSELY AFFECTED BY EXHAUST HEAT.

WARNING: INSTALLATION OF ANY TYPE OF "WRAPPING" MATERIAL ONTO THE HEADERS WILL DESTROY THE HEAT DISSIPATION PROPERTIES OF THE TUBING, CAUSING PREMATURE DETERIORATION OF THE METAL AND SUBSEQUENT FAILURE. USE OF ANY "WRAPPING" MATERIAL WILL VOID THE WARRANTY.

INSTALLATION INSTRUCTIONS FOR GIBSON SHORTY HEADERS GP129

INSTALLATION OF THESE HEADERS REQUIRES AN ADEQUATE WORKSPACE, GENERAL MECHANIC’S TOOLS, GENERAL MECHANIC’S KNOWLEDGE, AND A REASONABLE DEGREE OF EXPERIENCE. MOST AUTO-ENTHUSIASTS WITH THESE RESOURCES WILL HAVE LITTLE DIFFICULTY INSTALLING THESE HEADERS. HOWEVER, YOU SHOULD CAREFULLY READ THE INSTRUCTIONS BEFORE ATTEMPTING TO INSTALL THESE HEADERS. IF IN DOUBT, CONSULT A PROFESSIONAL MECHANIC.

1) PLACE VEHICLE IN A LOCATION WHERE THE FLOOR IS SOLID,FLAT, AND HAS ADEQUATE LIGHTING. DO NOT WORK WITH A HOT ENGINE!!! HEAT CAUSES METAL TO EXPAND AND MAKES REMOVAL OF FASTENERS DIFFICULT. DISCONNECT THE NEGATIVE BATTERY CABLE. RAISE THE FRONT OF THE VEHICLE TO OBTAIN ADEQUATE ACCESS TO THE BOTTOM OF THE MANIFOLD FLANGES. USE LARGE BASE JACKSTANDS TO SUPPORT THE VEHICLE. DO NOT RELY ON THE JACK!! BLOCK THE TIRES TO PREVENT THE VEHICLE FROM ROLLING OFF THE JACKSTANDS.

2) FIRST, DISCONNECT THE SPARK PLUG WIRES BY GRASPING AND GENTLY TWISTING THE SPARK PLUG BOOT. DO NOT PULL ON THE PLUG WIRES.SPRAY WD-40 OR SOME TYPE OF PENETRATING OIL ON ALL ACCESSIBLE FASTENERS BEFORE ATTEMPTING TO REMOVE THEM.

3) MARK ALIGNMENT OF THE SHAFT BEFORE REMOVING,THEN REMOVE THE BOLT FROM THE STEERING SHAFT. SLIP STEERING SHAFT APART. NOW UNBOLT THE MANIFOLDS FROM THE STOCK EXHAUST SYSTEM.

4) REMOVE THE SIX BOLTS HOLDING THE EXHAUST MANIFOLD TO THE HEAD, THEN REMOVE THE MANIFOLD. WITH THE MANIFOLD OUT OF THE WAY, CLEAN ANY CARBON DEPOSITS ON THE HEAD WITH A WIRE BRUSH. PREPARE THE SUPPLIED HEADER BOLTS WITH A SMALL AMOUNT OF ANTI-SEIZE TO THE THREADS.

5) INSTALL THE NEW HEADER USING THE SUPPLIED HEAD GASKETS, BOLTS, AND LOCK WASHERS. TIGHTEN THE GIBSON HEADERS FROM THE MIDDLE BOLTS TO OUTSIDE BOLTS.

6) RE-INSTALL THE SPARK PLUG WIRES AND RECONNECT THE STEERING SHAFT ON THE ALIGNMENT MARK.

7) ON THE PASSENGER SIDE REMOVE SPARK PLUG WIRES AND SPARK PLUGS AND SET ASIDE. REMOVE THE BOLT ATTACHING THE DIPSTICK TUBE BRACKET TO THE HEAD. THEN REMOVE THE DIPSTICK. DO NOT LOSE THE DIPSTICK BOLT YOU WILL NEED TO RE-USE IT.

8) REMOVE THE SIX BOLTS ATTACHING THE MANIFOLD TO THE HEAD. REMOVE THE MANIFOLD.CLEAN THE SURFACE OF THE HEAD. REMOVE ANY CARBON DEPOSITS THAT MAY BE ON THE HEAD.PREPARE THE SUPPLIED HEADER BOLTS WITH ANTI-SEIZE TO THE THREADS.

9) INSTALL THE NEW HEADER USING THE SUPPLIED HEAD GASKETS AND BOLTS. TIGHTEN THE GIBSON HEADERS FROM THE MIDDLE BOLTS TO THE OUTSIDE BOLTS. WE SUGGEST USING ULTRA COPPER GASKET SEALER ON BOTH OF THE HEAD GASKETS. . DO NOT use a sealant that is not designed to be used with 02 sensors. . . (Also note that if excessive sealant is applied, clumps may fall into the exhaust system and clog the Catalytic Converter.) Apply a thin coating of sealant to the supplied bolts and lock washers Torque all fasteners to approximately 30-35ft. lbs.

10) RE-INSTALL THE DIPSTICK TUBE. WRAP SPARK PLUG BOOT WITH HEAT WRAP PROVIDED AND RE-INSTALL. USING THE NUTS AND BOLTS PROVIDED, RECONNECT THE HEADERS TO THE STOCK EXHAUST UNDERNEATH THE VEHICLE.

NOTE: On some models, may need to bend heat shield out of the way on passenger side header. Due to header tube being very close to heat shield. (Only some models.)

11) FINALLY, MAKE SURE ALL BOLTS ARE TIGHT AND EVERYTHING IS RE-CONNECTED. START THE ENGINE AND LET IT WARM UP. CHECK FOR LEAKS. TURN ENGINE OFF AND MAKE SURE ALL BOLTS ARE TIGHT.

RE-TORQUE HEADERS AFTER 100-200 MILES
PERIODICALLY CHECK AND RE-TIGHTEN THE HEADER BOLTS. IF YOU DON’T RE-TORQUE YOUR HEADER BOLTS YOU COULD DEVELOP A LEAK AT THE HEAD GASKET.
THIS IS NOT COVERED UNDER WARRANTY.

IT IS CRITICAL THAT ALL BOLTS BE RE-TIGHTENED HOT AFTER ABOUT 20 MINUTES OF OPERATION TO PREVENT GASKET FAILURE.

NOTE: HEADERS ARE NOT MEANT TO SERVE AS “EXHAUST SYSTEM SUPPORT HANGERS”. ADDITIONAL HANGERS MAY NEED TO BE ADDED AT THE TIME OF THE INSTALLATION OF THE HEADERS SO THAT THE EXHAUST SYSTEM SUPPORTS ITSELF WHEN THE COLLECTOR BOKTS ARE REMOVED. HEADERS THAT HAVE “SAGGED” DUE TO THE LACK OF SUFFICIENT EXHAUST SYSTEM SUPPORT WILL NOT BE REPLACED UNDER WARRANTY.

NOTE: HEADER BOLTS SHOULD BE INSPECTED FOR TIGHTNESS FROM TIME TO TIME TO ENSURE OPTIMUM GASKET LIFE. THE BOLTS WILL STRETCH SOME AT FIRST DUE TO THE EXHAUST HEAT; SO, THEY’LL LOOSEN WITHOUT TURNING UNTIL THEY “TAKE A SET”. (BOLTS HARD ENOUGH NOT TO STRETCH WOULD BREAK!) WE’VE EXPERIMENTED WITH THE VARIOUS “LOCKING DEVICES” ON THE MARKET, WHICH PREVENT BOLTS FROM TURNING. THEY DON’T WORK ON HEADER BOLTS, AND THEY GREATLY COMPLICATE THE PROCESS OF RE-TIGHTENING THE BOLTS WHEN IT’S NECESSARY.

WHAT DOES WORK IS THIS:

GO OVER THE BOLTS AGAIN AFTER THE FIRST DAY OF DRIVING (OR ABOUT 100 MILES-WHICHEVER COMES FIRST) THEN AFTER THE FIRST WEEK, AFTER THE FIRST MONTH, AND THEN EVERY 6 MONTHS. OUR EXCLUSIVE GASKETS ARE SPECIALLY MADE SO THAT THE CYLINDER HEAD SHOULD BEGIN TO MELT BEFORE THE GASKETS CAN BURN UP. ABOUT THE ONLY WAY TO KILL THE GASKETS IS TO LET THE HEADERS GET LOOSE AND THEN KEEP DRIVING WITH A LEAK.

DUE TO VARYING CONDITIONS BETWEEN GEOGRAPHICAL LOCATIONS AND USAGE, WE STRONGLY RECOMMEND HAVING THE ENGINE RE-TUNE AT A REPUTABLE TUNE-UP SHOP AFTER THE INSTALLATION OF THE HEADERS. DOING SO WILL ENSURE THAT YOU GET THE MAXIMUM BENEFIT FROM THE INSTALLATION OF THE HEADERS.

GIBSON PERFORMANCE STRIVES TO DELIVER THE HIGHEST QUALITY MATERIALS, WORKMANSHIP, AND SERVICE. PLEASE SO NOT HESITATE TO CALL OUR TECHNICAL LINE IF YOU HAVE A QUESTION OR EXPERIENCE A PROBLEM.