GP137 CHROME HEADER NO AIR INJECTION, NO EGR 2014 SILVERADO / SIERRA TRUCK 1500 5.3L & 6.2L 2/4WD 2015 TAHOE/YUKON 5.3L GIBSON HEADERS ARE 50 STATE SMOG LEGAL Thank you very much for purchasing our Gibson header for your vehicle. If you need further assistance, please do not hesitate to call our Technical Department at (800) 528-3044 Monday through Friday 8:00 a.m. to 5:00 p.m. PST.
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.
SUGGESTED TOOLS 10mm, 13mm, 12mm” WRENCHES (VARIOUS LENGTHS) 10mm, 12mm, 13mm” SOCKETS (SHALLOW AND DEEP) 9/16” WRENCHES (VARIOUS LENGTHS) 9/16” SOCKETS (SHALLOW AND DEEP) 5/8” SPARK PLUG SOCKET 15MM DEEP SOCKET/SHALLOW 15MM BOX END WRENCH 3”, 6”, AND 12” EXTENSIONS FOR SOCKETS GOOD RUST PENETRANT
INSTALLATION INSTRUCTIONS FOR GIBSON SHORTY HEADERS GP137 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.
6) RE-INSTALL THE SPARK PLUG WIRES, DIP STICK TUBE, AND RECONNECT THE STEERING SHAFT ON THE ALIGNMENT MARK. 7) ON THE PASSENGER SIDE REMOVE SPARK PLUG WIRES AND SPARK PLUGS AND SET ASIDE. 8) REMOVE THE FIVE BOLTS ATTACHING THE MANIFOLD TO THE HEAD. REMOVE THE MANIFOLD FROM THE TOP OF THE VEHICLE.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.
10) 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.
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.
