PATRIOT H8403 Full Length Header Ford Mustang Small Block Instruction Manual
- June 9, 2024
- PATRIOT
Table of Contents
EXHAUST PRODUCTS
A PerTronix Performance Brand —
www.poertronixbrands.com — 909 599-5955
H8403 Full Length Header Ford Mustang Small Block
Installation Instructions & Warranty Information
H8403 ~ Ford
260-302
65-73 Mustang, 66-70 1/2 Falcon, 66-70 Fairlane, 66-76 Ranchero, 68-76 Torino,
67-73 Cougar, 66-77 Comet, 69-77 Maverick, 68-76 Montego, 66-72 Cyclone
351W
71-73 Mustang, 66-70 Falcon, 66-70 Fairlane, 66-76 Ranchero,
68-76 Torino, 71-73 Cougar, 68-76 Montego, 66-72 Cyclone
Long Tube Headers
1965-74 models
4 PERTRONIX PERFORMANCE BRANDS EMISSIONS CODES
This Product is considered a Replacement Part per CARB and EPA regulations for
emissions compliance and Is legal for sale and use on specified vehicles in
all 50 states as stated in Manufacturer’s Application Guide and Installation
Instructions.
1975-77 models
3 PERTRONIX PERFORMANCE BRANDS EMISSIONS CODES
This Product is LEGAL for Closed Course Competition use or Pre-Emissions
Controlled Vehicles ONLY. It is Not Legal for use on any Emissions Controlled
Vehicle for Street or Off Highway use.
REV. 9 5-16-22 DSL
PLEASE READ BEFORE PROCEEDING
PerTronie© thanks you for choosing a Patriot Exhaust Product. To realize the
potential of Patriot’s engineering and excellent fit, Please Read and
Understand these instructions completely prior to starting the installation.
Check that you received all the parts listed on the parts list, if you have
any concerns, please contact PerTronix before continuing. Headers will have
the part number stamped in the flange.
Work Smart — Work Safe! Most Header and Exhaust Installation are best
performed on a lift. If a lift is not available, raise the vehicle and support
on quality Jack Stands on level ground. Do not rely on a jack!
Many factors affect he installation of exhaust headers, including worn or
aftermarket motor mounts, previous accident damage, aftermarket cylinder heads
that may have relocated port or spark plug locations, suspension and steering
changes, sagging of original unibody structures due to age.
Coating Notes: Coatings can be marred during installation if you are not
careful. If you are breaking in a new motor, the extreme heat can alter the
appearance of the coating and this is not a warranty issue. We recommend
breaking in new motors with stock manifolds or an old set of headers.
We use sealing beads on all our headers. The raised bead creates a better seal
virtually eliminating leaks if installed properly. It is important to install
all header bolts lightly snug and then tighten to factory torque specs
starting in the center and working outward.
Before starting, allow the vehicle to cool, disconnect the battery, and spray
a penetrating oil on all hardware and fittings that will need to be removed.
Once you remove your manifold, clean the sealing surface on the head of any
old gasket debris or carbon build up.
- Will Not fit 71-73 Mustang/Cougar with Manual Transmission
- Factory Power Steering requires bracket part #H7609
- Will Work with Borgeson Power Steering Conversion as well.
DISASSEMBLY
- Remove and mark all spark plug wires and then remove all spark plugs.
- Disconnect the head pipes from the exhaust manifolds and remove the manifolds.
- Remove the clutch linkage (if manual transmission)
- Remove the power steering ram from the frame.
- Remove any gasket material or any carbon deposits that remain on the head surface.
INSTALLATION
-
Apply a small amount of anti-seize to the header bolts supplied with the headers.
-
Start the left header from below and work it up through the chassis into position over the exhaust ports.
Note: Mavericks / Comets require the removal of the center motor mount bolt and raising the engine approximately 2”. USE A BOARD BETWEEN THE OIL PAN AND JACK. -
With the header loose, replace the clutch linkage (if removed).
-
Start all the header bolts and tighten evenly.
Note: Engines with a Cobra oil pan may require denting the header tubes for adequate clearance of the pan.
Note: Some vehicles may require trimming the motor mount if it contacts the header tube.
Note: 1969 and later models may require denting the firewall for clearance if the L-4 tube makes contact. -
Tighten all the header bolts evenly starting in the center.
-
Reinstall the power steering ram with a purchased bracket P/N H7609. It may be necessary to reroute the power steering lines for header clearance.
Note: Mavericks / Comets: Check header for clearance of power steering ram. Dent tube (s) as needed for clearance. -
Automatic Transmission: Check the kickdown linkage. It may be necessary to bend the linkage towards the engine until it will work properly. Check the steering lockout rod, which may also require bending (to fit) or removal. If removed, the linkage to which it was attached must be wired in place to prevent steering from locking while the vehicle is moving.
-
Replace the spark plugs. When you install the spark plugs, apply a small amount of anti-seize to the threads.
-
Start the right header from below and work it up through the chassis into position over the exhaust ports.
-
Start all the header bolts and tighten evenly
Note: 1976 Mavericks / Comets: The vacuum canister must be moved at least ½” sideways (to clear #4 tube) and remounted.
Note: It may be necessary to reroute the automatic transmission cooling lines and/or starter cables for adequate header clearance. -
Tighten all the header bolts evenly starting in the center.
-
Replace the spark plugs. When you install the spark plugs, apply a small amount of anti-seize to the threads.
-
If the collector contacts the emergency brake cable, the bracket must be relocated so the cable will clear. See Figures A & B on Page 4.
-
Use the supplied reducers to connect the collectors to your stock exhaust system.
-
Connect the negative battery cable.
IMPORTANT CHECK LIST
- Be sure that all brake lines, transmission 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 dipstick tube was removed, make sure it is installed properly and that the dipstick has been replaced.
- Double-check the tightness of all bolts including brackets and accessories.
START THE ENGINE
Start the engine and allow it to warm up to operating temperature. Check for
any unusual noises or exhaust leaks. If everything 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
1 Left side header
2 Reducers
2 3” flat gaskets
6 3/8”-16 x 1” hex head cap screws| 1 Right side header
2 Header gaskets
16 3/8”-16 x 3/4” header bolts
6 3/8”-16 hex nuts
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WARNING: This product can expose you to chemicals including Lead, Nickel, Cadmium and Chromium which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov
PATRIOT EXHAUST LIMITED WARRANTY
All Patriot Headers and Exhaust products are guaranteed, to the original
purchaser, to be free of defects in material and workmanship for one year from
date of purchase. This warranty covers the replacement or repair of the
product and does not cover the cost of removal and installation, customer
applied coatings, or Any discoloration or corrosion of finished surfaces.
Damage or product failure resulting from collision, improper installation, off
road use, road hazards, the use of exhaust insulating wrap, or rust occurring
after installation is not covered by the warranty. This warranty extends only
to the original purchaser.
Should a part be deemed defective, it should be returned to the original
selling retailer and must be accompanied by the sales receipt. If there is no
retailer in your area, contact PerTronix direct for a return authorization and
return the part prepaid to the factory for inspection. PerTronix reserves the
right to replace or repair the alleged defective part and return the part
freight collect.