HEADERS #6502
Applications: 2001-2002 GM 1500/2500 Series Pick-Up,
Avalanche, Suburban, Tahoe, Yukon
4.8L/5.3L/6.0L V-8 Auto, 2 & 4 WD Dual Catalytic
without A.I.R. or EGR
2003 Hummer II 6.0L V8 without A.I.R. or EGR
INSTALLATION INSTRUCTION
PLEASE study these instructions carefully before installing your Headers. If you have any questions or
problems, please call our Technical Hotline at: 1-800-416-8628 from 8:00 am - 5:00 pm, Monday-Friday, Pacific
Standard Time or e-mail us at edelbrock@edelbrock.com.
HEADERS: These components are designed to improve the exhaust efficiency of the GM C.P.I. (Central Port
Injection) V8 engine. This system does not require welding for installation and retains all O.E.M.
emissions equipment. These Edelbrock headers are street legal in all 50 states.
SUGGESTED TOOLS FOR INSTALLATION: This vehicle has metric fasteners.
3/8” ratchet socket set with extensions and universal 13mm and 15mm swivel sockets
Set of combination wrenches
Jackstands, screwdrivers, pliers, crescent wrench, etc.
Liquid penetrant, (GM #1052627) anti-seize compound (GM #5613695)
SPECIAL NOTICE: This Edelbrock part has received an Executive Order from the California Air Resources
Board (C.A.R.B.) making it legal for street use on pollution-controlled motor vehicles in all 50 states. To assist
you with emissions equipment certification, we have included a silver fan shroud decal to help testing personnel
verify that this part is a legal replacement part on the vehicle for which it is cataloged. The adhesive-backed
decal should be affixed to your fan shroud next to the existing emission and engine specification decal. Do not
cover your original equipment specification decal with the Edelbrock fan shroud decal.
WARNING: The use of “Thermal Wrap” or any aftermarket coating process will void the warranty
headers. Those products can cause excessive heat and moisture buildup resulting in corrosion and early failure of
the system.
NOTE: High temperature spark plug wires and boots are recommended to withstand heat from Headers.
DISASSEMBLY
1. Disconnect negative battery cable.
2. Unbolt exhaust pipes from manifolds.
RIGHT SIDE
1. Disconnect and remove spark plug wires. 1. Disconnect and remove spark plug wires.
2. Unbolt dipstick tube. 2. Unbolt and remove manifold.
3. Unbolt and remove manifold.
4. Install flange gasket and header from top. Install
header bolts, lock washers, and thick flat washers
supplied, ensure proper alignment and tighten
bolts.
Note: Thick washers are to be used on slotted
holes of port flange.
5. Re-install spark plug wires.
6. Re-fasten dipstick tube.
LEFT SIDE
3. Install flange gasket and header from top. Install
header bolts, lock washers, and thick flat washers
supplied, ensure proper alignment and tighten
bolts.
Note: Thick washers are to be used on slotted
holes of port flange.
4. Re-install spark plug wires.
Note: Due to production tolerance, it may be
necessary to bend the motor mount heat shield for
better clearance.
on your
ASSEMBLY OF EXHAUST PIPE FINAL INSPECTION
Note: The stock donut on 4.8L & 5.3L gasket on
right exhaust manifold will be re-used with
headers.
This system comes with 2 exhaust crush
rings. On 4.8L & 5.3L V8s, one will be
used on the left side collector. 6.0L
vehicles will use one on the left side and
one on the right side to replace factoryinstalled crush rings.
1. On 4.8L & 5.3L V8s - Remove the donut gasket
from right side exhaust manifold. Using a pair of
pliers, remove the retaining ring from the donut
gasket and place the donut gasket in flare of
factory exhaust pipe.
2. Using supplied hardware, re-attach the factory
exhaust pipes to the headers and tighten bolts
evenly to ensure a tight seal. (Note: The 7/16 x 2
bolts are to be used on the right side of 4.8L &
5.3L V8s and the 7/16 x 1 ¾ are for the left side of
4.8L & 5.3L V8s, or both sides on 6.0L V8).
HARDWARE SUPPLIED
Qty. Description Qty. Description
1. Check all lines (hydraulic, vacuum, air
conditioning and fuel) to ensure there is
adequate clearance to headers.
2. Re-connect battery.
3. At this point, it is a good idea to look
everything over and make sure that nothing
was missed in assembly.
4. Start vehicle and bring up to normal operating
temperature. Check for possible leaks.
5. Turn engine off and let cool. Tighten all bolts
again.
1 #25-9174 Header left side 6 7/16” Lock washers
1 #25-9156 Header right side 6 7/16” Hex Nuts
4 Hex header bolts; 8mm x 1.25 x 30mm 6 7/16” Flat washers
8 Hex header bolts; 8mm x 1.25 x 25mm 14 5/16” Lock washers (header flange)
2
Port gaskets
3
7/16” x 2 Hex bolts
6 7/16” x 1 ¾ Hex bolts
2 Exhaust crush rings
PLEASE complete and mail your warranty card. Be sure to write the model number of this product in the “Part
#______” space. Thank you.
4 Hardened washers (for header flange) slotted
holes
Edelbrock Corporation
2700 California Street
Torrance, California 90503
Toll-Free Tech Line (800) 416-8628
Tech E-mail: edelbrock@edelbrock.com
2002 Edelbrock Corporation Rev. 8/02
C:\WINWORD\Installation Instruction - Temp Folder\6502 - Shorty Headers.Doc