Edelbrock 68642 User manual

Catalog #s 68642, 68643, 68652, 68653
©2006 Edelbrock Corporation Page 1 of 3
Brochure #63-68642
Rev. 5/06 - DA/mc
®
TUBULAR EXHAUST SYSTEM
Vehicle Applications: See Below
Catalog #68642, #68643
#68652, #68653
INSTALLATION INSTRUCTIONS
Please study these instructions carefully before installing your new Tubular Exhaust System (TES). If you have any
questions, please contact our Technical Hotline at : 1-800-416-8628 from 7 am - 5pm, Monday-Friday, Pacific
Standard Time or e-mail us at [email protected]. Please fill out and mail your warranty card.
TUBULAR EXHAUST SYSTEM: These components are designed as a system to improve the exhaust efficiency of the GM
T.B.I. (Throttle Body Injection) V6 engine. A performance gain can be expected by the installation of the system. This
system does not require welding for installation and retains all O.E.M. emissions equipment.
APPLICATIONS:
Catalog #s 68642 / 68643 - 1987-1991 Chevy/GMC Suburban 1500/2500 Series with, 5.7L V8 T.B.I., 2 & 4 W.D.,
Auto and Standard Transmission without A.I.R.
Catalog #s 68652 / 68653 - 1987-1991 Chevy/GMC Suburban 1500/2500 Series with, 5.7L V8 T.B.I., 2 & 4 W.D.,
Auto and Standard Transmission with A.I.R.
Suggested Tools Needed for Installation: This vehicle has some 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)
NOTE: Some models will require a special power steering pulley puller; K-D 2897 or equivalent.
SPECIAL NOTICE: This Edelbrock Tubular Exhaust System 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
Tubular Exhaust Systems. Those products can cause excessive heat and moisture buildup resulting in corrosion and
failure of the system.
NOTE: High temperature spark plug wires and boots are recommended to withstand heat from T.E.S.
IMPORTANT NOTE:
Proper installation is the responsibility of the installer. Improper installation will void warranty and may
result in poor performance and engine or vehicle damage.

Catalog #s 68642, 68643, 68652, 68653
©2006 Edelbrock Corporation Page 2 of 3
Brochure #63-68642
Rev. 5/06 - DA/mc
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. Making sure the converter is cool, remove the
exhaust crossover pipe.
5. Lower vehicle to the ground.
DISASSEMBLY LEFT SIDE
1. Remove air cleaner system (note position of line and
hose connections).
2. Disconnect A.I.R. (air injection reactor) tube from
exhaust manifold (#68652 & #68653 only).
3. Remove air conditioner compressor rear support
bracket (if air conditioning equipped).
4. Remove power steering pump support bracket (if
power steering is applicable).
5. Disconnect spark plug wires and remove spark
plugs.
6. Remove O2 sensor, being careful not to rupture or
destroy the unit.
WARNING: Do not clean this unit in any cleaning
solvent and do not rupture wire.
7. Disconnect temperature sensor wire.
8. Remove bolts and exhaust manifold from top side.
DISASSEMBLY RIGHT SIDE
1. Disconnect A.I.R. injection tube from exhaust
manifold (#68652 & #68653 only).
2. Disconnect spark plug wires and remove spark
plugs.
3. Remove bolts and exhaust manifold from top side.
4. Clean exhaust flange surfaces on cylinder heads at
this time.
ASSEMBLY LEFT 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 left side T.E.S. manifold from top side.
3. Install all but the front two bolts and washers on left
side (do not tighten at this time).
INSTALLATION INSTRUCTIONS
4. Re-install rear power steering support bracket. Do
not tighten at this time.
5. Re-install rear A/C support bracket with bolts, lock
washers, and spacers supplied.
6. Align all parts and tighten left side bolts and nuts at
this time.
7. Re-install spark plugs and re-connect wires on left
side.
8. Re-install temperature sensor wire to temperature
sensor.
9. Re-install 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).
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 right side T.E.S. manifold from top side.
3. Install remaining bolts, lock washers, and spacer
tube for dipstick to clear exhaust flange.
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 T.E.S. With hose supplied in
kit, re-connect all A.I.R. injection hoses at this time
((#68652 & #68653 only).
7. Raise vehicle and support with jackstands.
CROSSOVER PIPE ASSEMBLY
1. Carefully align and tap adapter tube into converter
using a piece of wood or a mallet to protect the end of
the adapter.
NOTE: Be sure adapter goes all the way in,
approximately 2-1/2".
2. Install crossover pipe assembly on vehicle using four
3/8" x 2" bolts with lock washers and donut gaskets
supplied.
3. Install U-clamps and position for maximum ground
clearance, then tighten all nuts and bolts.

Catalog #s 68642, 68643, 68652, 68653
©2006 Edelbrock Corporation Page 3 of 3
Brochure #63-68642
Rev. 5/06 - DA/mc
Qty. PN Description
❑ 1 25-9526 Extension pipe left side
❑ 1 25-9527 Extension pipe right side
❑ 1 - Pigtail O2 sensor; 12”
❑ 4 - Flat washers; 3/8”
❑ 1 - O2 Sensor plug
❑ 12 - Hex header bolts; 3/8” x 1”
❑ 2 - Ferry bolts; 3/8” x 2-3/4”
❑ 1 - Flange connector
❑ 1 - U-Clamp; 2-1/4”
❑ 1 - U-Clamp; 3”
❑ 2 - Chevy V6 port gaskets
❑ 2 - Donut gaskets; 2-1/4”
❑ 1 - Hose (A.I.R.); 5/8” x 30” (#68652 & #68653 only)
❑ 1 - Hex bolt; 1/4”-20 x 1”
❑ 4 - Hex bolt; 3/8”-16 x 2”
❑ 1 - Adapter; catalytic converter
❑ 1 - Spacer tube; 3/8” O.D. x 1/2” long
❑ 2 - Spacer tube; 5/8” O.D. x 1-1/2” long
❑ 16 - Lock washers; 3/8”
Qty. PN Description
❑125-9431 Header left side (#68642)
❑125-9430 Header right side (#68642)
❑125-9028 Header left side (#68643)
❑125-9023 Header right side (#68643)
KIT CONTENTS
Catalog #68642, Catalog #68643 (Ti-Tech Coated)
Edelbrock Corporation, 2700 California St., Torrance, CA 90503
Tech Line: 1-800-416-8628
E-Mail: [email protected]
Qty. PN Description
❑1 25-9429 Header left side (#68652)
❑1 25-9428 Header right side (#68652)
❑ 1 25-9028 Header left side (#68653)
❑ 1 25-9019 Header right side (#68653)
KIT CONTENTS
Catalog #68652, Catalog #68653 (Ti-Tech Coated)
KIT CONTENTS
Common to All Part Numbers