Edelbrock Header
Catalog #6527
For 1979-1987 Chev/GMC Pick Up, Suburban and
1983-1986 Blazer, Jimmy 5.0L, 5.7L V8
INSTALLATION INSTRUCTION
Please study these instructions carefully before installing your new Header. If you have any questions or problems, please
contact our Technical Hotline at : 1-800-416-8628from 7 am - 5pm, 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 GMV8 engine. This system does
not require welding for installation (see note below) and retains all O.E.M. emissions equipment. These Edelbrock
headers are street legal in all 50 states.
SPECIAL NOTE: Read Carefully Before Beginning Installation
Before beginning installation of your new shorty headers, you will need to first determine whether or not these shorty
headers will fit your vehicle without additional modifications to your factory stock exhaust system. GM used several
different styles of exhaust manifolds on the model year vehicles listed above.
The most common exhaust manifolds used on the above-listed vehicles are down swept manifolds; meaning, the stock
exhaust manifolds when installed sweeps under the spark plugs as seen in
Figure 1. Note the location and position of the outlet of the left (driver’s side)
manifold. Part #6527 is a direct replacement for stock exhaust manifolds as
shown in Figure 1. Some vehicles within the above year coverage came with
exhaust manifolds that rise up and over the spark plugs as shown in Figure 2.
Part #6527 is not a direct replacement for the upsweeped manifold. A new Ypipe will have to be fabricated or your stock one will need to be modified.
Most any muffler shop should be able to handle this.
Suggested Tools Needed for Installation: This vehicle has universal metric
fasteners.
❑ 3/8” rachet socket with extensions, metric and standard sockets
❑ Set of combination wrenches
❑ Jackstands, screwdrivers, pliers, crescent wrench, etc.
❑ Liquid penetrant, (GM #105627) and anti-seize compound (GM
#5613695)
❑ Spark plug terminal crimper
SPECIAL NOTICE: This Edelbrock part has received an Executive Order number
(E.O.#) from the California Air Resources Board (C.A.R.B.) making it legal for
street use in all 50 states. To assist you with emission equipment certification,
we have included a silver fan shroud decal to help testing personnel verify the
this part is a legal replacement on the vehicle for which it is cataloged. The
adhesive-backed decal should be affixed next to the existing emission and
engine specifications decal. Do not cover any part of your original emission
decal.
WARNING: The use of "Thermal Wrap" or any aftermarket coating process will void the warranty on your Edelbrock
Headers. Those products will cause excessive heat and moisture buildup resulting in corrosion and failure of the header.
Note: High temperature spark plug wires and boots are recommended to withstand heat from headers.
Fig. 1
Fig. 2
Catalog PN 6527
Page 1 of 3 Rev. 5/02
INSTALLATION INSTRUCTIONS
Disassembly
1. Disconnect battery negative cable from battery.
2. Raise vehicle and support with jackstands.
3. Use penetrating oil on all nuts and bolts to be
removed. This will prevent the possibility of broken or
stripped nuts and bolts.
4. Disconnect and remove O2 sensor ( if equipped).
5. Making sure the converter is cool. Remove exhaust
pipes from manifold and catalytic converter.
6. Remove heat riser valve from right side manifold. Put
aside for re-use.
7. Remove air cleaner system (note position of line and
hose connections).
8. Disconnect A.I.R. (Air Injection Reactor) hose from air
tube check valve on both sides.
9. Remove air conditioner compressor rear support
bracket (if air conditioning equipped).
10. Remove power steering pump support bracket (if
power steering is applicable).
11. Disconnect spark plug wires and remove spark plugs.
12. Disconnect temperature sensor wire.
13. Disconnect and remove vacuum pod from right side
manifold.
14. Remove bolts and exhaust manifolds from top side.
15. Clean exhaust flange surfaces on cylinder heads at
this time.
Assembly - Left Side
s1. Install O2 sensor plug in left side manifold.
2. Install TES flange gasket and one 3/8”-16 x 1” bolt,
lock washer, and flat washer at rearmost bolthole
(leave bolt loose enough to accept TES).
3. Install left side TES manifold from top side.
4. Install all but the front two bolts and washers on left
side (do not tighten at this time).
5. Re-install rear power steering support bracket. Do
not tighten at this time (if vehicle is equipped).
6. On vehicles equipped with long A/C compressor,
install supplied A/C support bracket using supplied
bolts, lock washers, and hardened washers. On
vehicles equipped with short A/C compressor, use
1-1/2” long spacers on front two bolts behind original
A/C bracket, use long 12-point bolts, lock washers,
and hardened washer that are supplied.
7. Align all parts and tighten left side bolts and nuts at
this time.
8. Remove all four spark plug boots and terminals.
9. Replace with 90-degree terminals and boots.
10. Re-install spark plugs and re-connect wires on left
side.
11. Re-install temperature sensor wire to temperature
sensor.
Assembly - Right Side
1. Install TES flange gasket and one 3/8”-16 x 1” bolt,
lock washer and flat washer at rearmost bolthole
(leave bolt loose enough to accept TES).
2. Install right side TES manifold from top side.
3. Install vacuum pod and bracket using bolts and 3/4”
spacers supplied. Install remaining bolts and lock
washers.
4. Align all parts and tighten all right side bolts at this
time.
5. Re-install spark plugs and re-connect wires.
6. Remove A.I.R., check valves from original manifolds
and re-install them on TES. With 3/4” hose supplied
in kit, re-connect all A.I.R. injection hoses at this time.
Crossover Pipe Assembly
1. Install heat riser valve with gasket and connect
actuating rod.
2. Install exhaust pipe assembly using three 3/8” x
2-1/2” hex bolts on right side header and three 3/8”
x 1-1/2” hex bolts on left side header.
3. Check for hose and wiring clearance around headers
and exhaust system.
Catalog PN 6527
Page 2 of 3 Rev. 5/02