Edelbrock 6525 user manual

EDELBROCK HEADER - CATALOG #6525

for 1998-2000 Pick-Up 5.0L, 5.7L V8 CPI with A.I.R. &

1998-2000 Suburban, Blazer, Tahoe, Jimmy, Yukon, 5.0L,

5.7L CPI with A.I.R.

INSTALLATION INSTRUCTIONS

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 7:00 am - 5:00 pm, Monday-Friday, Pacific Standard Time or e­mail us at [e-mail]. Please fill out and mail your warranty card.

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
❑ Combination set of open-end 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 (E.O. #) 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 on your
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. Raise vehicle and disconnect 02 sensors.

3. Unbolt stock exhaust pipes from manifolds.

Right Side

1. Remove air intake assembly.

2. Disconnect A.I.R. injection hose from exhaust
manifold check valve.

3. Disconnect spark plug wires from spark plugs.

4. Unbolt dip stick tube.

5. Unbolt and remove manifold.

6. 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.

7. Remore A.I.R. check valve from stock manifold and
install on A.I.R. fitting of header.

8. Connect A.I.R. injection hose to check valve.

9. Re-install spark plug wires.

10. Re-fasten dip stick tube using spacer and bolt
supplied in kit (if needed).

11. Re-install air intake assembly.

12. With wire ties, route any hoses, wires or lines away
from headers as necessary.

©2000 Edelbrock Corporation
Rev. 4/27/00

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Catalog #6525

Left Side

1. Disconnect spark plug wires from spark plugs.

2. Disconnect A.I.R. injection hose from exhaust
manifold check valve.

3. Disconnect E.G.R. tube from rear of manifold.
(Stock E.G.R. adapter fitting will be re-used.)

4. Disconnect temperature sensor wire.

5. Unbolt and remove manifold from top side.

6. Install flange gasket and one 3/8"-16 x 1" bolt,
lock washer, and flat washer at rearmost bolt
hole (leave bolt loose enough to accept Header).
NOTE: Thick washers are to be used on slotted
holes of port flange.

7. Install left side Header from top side.

8. Install all bolts and washers on left side (do not
tighten at this time).

9. Re-install E.G.R. tube to header using stock
adapter.

10. Align all parts and tighten left side flange bolts at
this time.

11. Remove A.I.R. check valve from manifold and
install on A.I.R. fitting of header.

12. Connect A.I.R. injection hose to check valve.

13. Re-install spark plugs wires.

14. Re-install temperature sensor wire to
temperature sensor.

ASSEMBLY OF EXHAUST PIPE

1. Using supplied hardware and new donut gaskets
on both sides, re-attach the factory extension
pipes to the headers, and tighten bolts evenly to
ensure a tight seal.

2. Re-connect O2 sensors. Route O2 sensor wire
from loom to O2 sensors away from exhaust
components.

FINAL INSPECTION

1. Check all lines (hydraulic, vacuum, air
conditioning and fuel) to ensure there is
adequate clearance to headers. Use wire ties as
needed.

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.

HARDWARE SUPPLIED

Qty. Description Qty. Description

❑ 1 #25-9161 Header left side ❑ 6 3/8” Flat washers
❑ 1 #25-9162 Header right side ❑ 1 1/4 Hex capscrew
❑ 12 Hex header bolts ❑ 4 Hardened washers (for header flange slotted holes)
❑ 2 Port gaskets ❑ 6 3/8” Hex nuts
❑ 2 Donut gaskets ❑ 1 3/8” O.D. spacer
❑ 6 3/8” Hex capscrews ❑ 3 Wire ties
❑ 18 3/8” Lock washers

Edelbrock Corporation

2700 California St.

Torrance, CA 90503

Tech Line: [phone]

Office: [phone]

E-Mail: [e-mail]

©2000 Edelbrock Corporation
Rev. 4/27/00

Page 2 of 2

Catalog #6525