Edelbrock 6661 User Manual

2. Remove O2 sensor, being careful not to rupture or
destroy the unit.

W ARNING: Do not clean this unit in any cleaning solvent

and do not rupture wire.

3. Making sure the converter is cool, remove the exhaust
crossover pipe. You may find it helpful to clamp the con­verter to the crossmember using pieces of wood and C­clamps. This will allow you to work the crossover pipe
loose from the converter more easily. If the pipe is frozen
to the converter, it can be heated with a Prop ane torch
(or equivalent) to help loosen the joint.

4. Unbolt air conditioning support bracket on frame and use
a crescent wrench to bend bracket end approximately 5
to move hoses away from exhaust manifold (see Figure

1).

ASSEMBLY - LEFT SIDE

1.Install T.E.S. flange gasket and one 3/8"-16 x 1" bolt, lock
washer, and f lat w ash e r at r ea rmost bolt hole (leave bolt
loose enough to accept T.E.S.).

2.Install left side T.E.S. manifold from bottom side.

3.Install all bolt s and washers on lef t s id e a nd ti ghten.

4. Replace original equipment spark plug ends on cylinders
#5 and #7 with 60 connectors and boot s provided in kit.

DISASSEMBLY - LEFT SIDE

1. Disconnect negative cable from battery.

2. Use penetrating oil on all nut s and bolt s to be removed.
This will prevent the possibility of broken or stripped nuts
and bolts.

3. Remove air cleaner system (note position of line and
hose connections).

4. Disconnect A.I.R. (air injection reactor) tube from exhaust
manifold (if applicable).

5. Disconnect spark plug wires.

6. Disconnect temperature sensor wire.

7. Remove bolts and exhaust manifold.

DISASSEMBLY - RIGHT SIDE

1. Remove air cleaner box.

2. Remove air conditioning hose bracket under air cleaner
box (if applicable).

3. Disconnect spark plug wires.

4. Remove dipstick and both sections of dipstick tube.

5. Remove bolts and exhaust manifold .

6. Clean exhaust flange surfaces on cylinder heads at this
time.

7. Drill two 7/32" holes in the inner fender well p anel and pull
heater hoses to panel and secure with clamps provided.

DISASSEMBLY - CROSSOVER PIPE

1. Raise vehicle and support with jackstands.

' 1998 Edelbrock Corp. Rev 4/98

S TAINLESS STEEL TUBULAR EXHAUST SYSTEM #6661

Application:

1992-’95 Chevrolet & GMC Suburban; 2500 Series, 2 & 4 W. D.,

7.4L V8 w/T.B.I., automatic & st d. transmission, w/o A.I.R.

INSTRUCTIONS

PLEASE study these instructions carefully before installing your new T ubular Exhaust System (T.E.S.). If you have any

questions or problems, do not hesitate to contact our Technical Hotline at : 1-800-416-8628.

TUBULAR EXHAUST SYSTEM: These components are designed as a system to improve the exhaust efficiency of the

GM 7.4 Liter T.B.I. (Throttle Body Injection) V8 engine. They are constructed of 409 HP stainless steel to better withst a nd
the high heat present with the T.B.I. engine, especially when used for towing or other heavy duty applications. The stai n ­less steel used for these systems is much more durable than mild steel, although it does not appear different in appear­ance. These systems come with a coat of black paint for good looks and protection during shipping and storage, and
they can be identified by the part numbers on each of the major components. Note that a magnet will stick to this type of
stainless steel; magnetic attraction is not a valid test for these systems. A performance gain can be expected by the
inst allation of the system. This system requires no welding for inst allation and ret ains all O.E.M. emissions equipment.

SUGGESTED TOOLS FOR INSTALLATION: This vehicle has some metric fasteners.

3/8 ratchet socket set with extensions and universal 13mm and 15mm swivel socket s
Combination set of open-end wrenches
Jackstands, screwdrivers, pliers, crescent wrench, etc.
Drill motor and 7/32" drill bit
Liquid penetrant, (GM #1052627) anti-seize compound (GM #5613695)

W ARNING: The use of Thermal Wra p materials will void the warranty on your Tubular Exhaust System. Those products

can cause excessive heat and moisture buildup resulting in corrosion of the system.

SPECIAL NOTICE: This Edelbrock part has received an Executive Order number (E.O. #) from the California A ir

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 p art is a legal replacement p art 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.

NOTE: High temperature spark plug wires and boot s are recommended to withstand heat from TES.

5. Re-connect spark plug wires on left side.

6. Re-inst all temperature sensor wire to temperature sensor.

ASSEMBLY - RIGHT SIDE

1.Install T.E.S. 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 T.E.S.).

2.Install dipstick tube and right side T.E.S. manifold from top
side.

3.Install remaining bolts and lock washers. Use original
equipment stud-bolt to re-attach dip stick bracket.

4. Align all p art s and tighten all right side bolt s at this time.

5. Replace original equipment spark plug ends on cylinders
#4, #6 and #8 with 60 connectors and boot s provided in
kit.

6. Re-connect right side spark plug wires.

7. Discard O.E.M. heat stove pipe and replace with flexible
tubing supplied (if applicable).

8. To prevent cont act with the hot T.E.S. tubing, use nylon tie
wrap (supplied) to secure the heater hose to the a.c.
dryer.

PLEASE complete and mail your warranty card. Be sure to write the model number (#6661) in the Part #____ space.

THANK YOU.

Figure 1
Bend air conditioning support bracket approximately 5 using crescent wrench. Be sure that there is adequate clearance
between the hose’s aluminum tubing and right side inner fender panel after support bracket is bent.

CROSSOVER PIPE ASSEMBLY

1. Slip crossover pipe into Y -pipe assembly and extension
tube onto Y-pipe assembly outlet (do not clamp).

2. Place donut gaskets o n extensions and slip tube into
muffler inlet. Align p a rts and st art flange bolt s.

3. Check alignment of all pa rt s then secure bolt s .

4.Install U-clamp s and tighten all nuts and bolt s .

5. Re-inst all O2 sensor. Use anti-seize on threads of sensor
and torque to 30 ft./lbs. Re-route O2 sensor wire from
wire loom to O2 sensor making sure all wires are clear of
exhaust system (O2 sensor extension wire is included in
kit).

6. Lower vehicle to the ground.

CAUTION: Before operating you vehicle, check to

ensure that there is adequate clearance between all
part s of your TES (including A.I.R. tubes) and all brake
lines, fuel lines, sp ark plug wires, etc.

HARDWARE SUPPLIED
1- Manifold lef t side #25-9057
1- Manifold right side #25-9096
1- Extension pipe right side #25-

9563
1- Extension pipe left side #25-9562
1- Muf fler extension #25-9564
4- Flat washers, 3/8"
16 - Hex header bolts, 3/8"-16 x 1"
1- Flange connector
1- U-clamp, 2-1/2"
1- U-clamp, 3"
2- Chevy V8 port gaskets
2- Donut gaskets, 2-1/2"

1- Flex tubing, heat stove to air

cleaner
4- Hex bolt, 3/8"-16 x 2"
20- Lock washers, 3/8"
2- T ie wrap s, 10 "
1- Bolt 3/8-16 x 1-3/4"
1- S pacer tube 5/8 x .724"
2- Band-clamps
2- Hex nuts, 10-32
2- Hex cap screws, 10-32 x 1"
5- S park plug boots
5- S park plug boot ends
2-Star washers; 3/16"