PerTronix D6672 User Manual

Corporate Office: PerTronix Inc. 440 E. Arrow Highway, San Dimas, California 91773 * Phone [phone] * FAX [phone] * www.dougsheaders.com

The Installation of this header requires the use of the
factory dual hump transmission crossmember that came
on 1996-89 Mustang 5.0
This header requires the use of Accel Shorty spark plugs
#0574S or 0576S with 90° spark plug boots

HEADER INSTALLATION INSTRUCTIONS

D6672

PerTronix©

realize the full potential of our good fit, please read and understand these instructions completely prior to starting work.
Check to make sure you received the proper parts for your application. The header number will be stamped on the engine flange. If

you are unsure you have received the proper parts call before you start work.
Be sure to work safe! Whenever you work under the vehicle be sure that it is located on level, solid ground and is supported by

adequate safety stands! Remember: Hot asphalt will not support most jack stands!
Many factors affect the installation of headers, some of which are broken or aftermarket motor mounts, accidents that impact the

configuration of the frame, and/or the installation of different engines or aftermarket cylinder heads. Most installations require some
welding. If you are uncomfortable with welding operations, we recommend that you contact a professional exhaust system specialist
to install your new headers.

Attention Customers breaking in new engines: Due to the extreme heat generated during the break-in process, the appearance of
the ceramic coating may be altered in certain areas. The protection characteristics and thermal barrier properties of the coating is
never compromised. It is recommended that a cast iron manifold or old set of headers be used for this process.

Notice: The coating of these headers can be marred or scratched during installation. If the header needs to be returned and is
damaged, you will be charged for recoat.

thanks you for choosing

1979-1993 FORD Mustang, 351W

DOUG’S HEADERS

, the best fitting, highest quality header on the market. In order to

DISASSEMBLY

1. Disconnect the negative battery cable from the battery.

2. If a car lift is not available, raise the vehicle 2 feet or higher and support it with adequate safety
stands. Make sure the vehicle is on a flat solid surface and is stable.

3. Apply penetrating oil to all nuts and bolts to be removed.

4. Unbolt headpipe from stock exhaust manifolds.

5. Remove spark plugs and stock exhaust manifolds.

6. Remove O2 sensors, if so equipped.

7. Remove bottom A-arm to frame brace, (convertible models) and the oil dip stick and tube.

8. Loosen the starter cable so it can be moved for clearance.

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9. Replace the spark plugs finger tight so debris will not get into the cylinders while cleaning the
head surface.

10. Clean the cylinder head surface which mates to the header. Use a gasket scraper and wire
brush to make sure that the surface is absolutely clean.

11. After cleaning is complete remove the spark plugs again.

ASSEMBLY

1. Apply anti-seize to all header bolts being used.

2. Note: Because of various motor mount designs used between 1979 and 1993 some side
mounts may need to be trimmed for clearance of the R-4 tube. See Figure 1.

3. Apply a THIN film of Ultra Copper Hi-Temp Sensor-Safe Silicone Sealer to the header side of 2
supplied gaskets and glue them to the inner flanges. Now apply a THIN film of Ultra Copper Hi­Temp Sensor-Safe Silicone Sealer to the engine side of these gaskets.

4. Install the inner flanges and gaskets with the supplied allen head countersunk screws.

5. Apply a THIN film of Ultra Copper Hi-Temp Sensor-Safe Silicone Sealer to the header side of
the other 2 supplied gaskets and glue them to the headers. Masking tape can be used to help
stick the gaskets to the manifold.

6. Apply a THIN film of Ultra Copper Hi-Temp Sensor-Safe Silicone Sealer to the engine side of
the gaskets and, starting from below, work the left header up into place and start the header
bolts but leave them loose.

7. Apply a small amount of THIN film of Ultra Copper Hi-Temp Sensor-Safe Silicone Sealer to the
slip joints and install L-4 slip tube and start the bolts.

8. Tighten all bolts evenly.

9. On the right side, from the bottom, work R-4 into position in front of the starter. Do not start
bolts yet.

10. Work tube R-3 on the outside of R-4, keeping it in front of the starter. Do not start bolts yet.

11. Hold R-4 to head at correct exhaust port and tighten cable on starter with it positioned for
maximum clearance.

12. Work the main body of the header from the bottom up over the top of the starter. Insert tubes
R-3 and R-4 into the slip joints.

13. Position gasket and start all bolts. Install R-2 slip tube and start bolts. Torque all bolts evenly.

14. Re-install engine oil dipstick tube and dipstick. Note: It may be necessary to bend the dipstick
tube in order to clear the headers and line up with the mounting tab.

15. Tighten the header bolts evenly to a final torque of approximately 25 ft. lbs.

16. Reinstall spark plugs and plug wires.

17. Install reducers and attach exhaust system to reducers.

18. Make sure all of the other fasteners are tightened.

19. Connect the negative battery cable.

IMPORTANT CHECK LIST

Be sure that all brake lines and fuel lines are clear of headers and/or connector pipes.
All spark plug wires, battery cables, or other electrical components should be clear of headers

and/or connector pipes.

If removed, make sure the dipstick is installed properly and that it has been replaced.
Double-check the tightness of all bolts including brackets and accessories.
Perform these checks again after the first 1000 miles.
Check clearance and tightness of front driveshaft.

Part No. 0110-003060 Page 2 12-19-06 sak

Trim off corner
as indicated

RIGHT SIDE MOTOR MOUNT

Figure 1

START THE ENGINE

Start the engine and allow it to warm up to operating temperature.
Caution! Hot parts! Wear protective clothing as needed.
Check for any unusual noises or exhaust leaks. If every thing is OK, stop the engine and
tighten all bolts while the engine is still warm.
NOTE: Check the bolts periodically to make sure they have not loosened. Re-tighten after the
first 500 miles and then again at 1000 miles.

PARTS LIST

Qty. Description

1 Right side header
1 Left side header
2 Inner flanges
4 Header / inner flange gaskets
2 Collector gaskets
2 Reducers

1 Decal:
1 Hardware kit:
16 5/16”-18 x 3/4” flanged header bolts
16 3/8”-16 x ½” Allen flathead countersunk screws
16 5/16” lock washers
6 3/8” lock washers
6 3/8”-16 x 1-1/4” hex bolts
6 3/8” hex nuts

DOUG’S HEADERS

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