Owners manual
Part No. 6901HKR (black paint), 6901-1HKR (silver ceramic),
6901-2HKR (stainless) and 6901-3HKR (Darkside black ceramic).
HOOKER COMPETITION FORD /MERCURY HEADERS
● 1966-73 Falcon, Fairlane, Torino, Ranchero, Cyclone, & Montego (255-302) ●
● 1964-73 Mustang / Cougar (255-302W) ●
● 1967-73 Mustang, Fairlane / Cougar (351W) ● 1966-69 Comet (255-302W) ●
● 1970-77 Maverick (255-302W) ●
NOTE: Will not fit a Dart Windsor head.
NOTE: Will not fit 1971-73 Mustang / Cougar with manual transmissions.
NOTE: Will fit C-6 transmissions.
Thank you for making HOOKER HEADERS your choice in a high-performance exhaust system. Extensive dyno/track testing has enabled HOOKER to offer
the most advanced design in exhaust systems. The installation, while not complex, will take a certain amount of time. However, the additional horsepower
and improved performance will more than justify your efforts. Proper installation and maintenance will ensure long life and maximum performance from your
HOOKER HEADER exhaust system.
WARNING! Breaking in an engine with ceramic-coated headers WILL result in damage to the coating and will VOID all warranties. Ceramic-
coated headers require several heat cycles to fully cure before they will withstand extreme heat. HOOKER recommends using a cast-iron exhaust
manifold or an old header to break in new engines to avoid coating damage.
BEFORE STARTING
Your vehicle must be raised a minimum of 36 inches. A floor hoist is ideal. If no hoist is available, we strongly urge the use of axle stands as a safety
measure. CAUTION! YOUR CAR SHOULD NOT BE SUPPORTED ON A BUMPER JACK.
INSTALLATION PROCEDURE: PLEASE READ CAREFULLY
LEFT SIDE:
1. Disconnect the negative battery cable to prevent damage to the electrical system.
2. Unbolt the headpipes (both sides) from the stock exhaust manifolds and muffler(s). Remove from the vehicle.
3. Remove the spark plugs and clutch linkage (if manual). Remove the power steering ram from the frame.
4. Starting from below, work the header up through the chassis into position over the exhaust ports.
NOTE: Mavericks / Comets require the removal of the center motor mount bolt and raise the engine approximately 2”. USE A BOARD BETWEEN THE OIL
PAN AND JACK.
5. With the header loose, replace the clutch linkage (if removed).
6. Insert the flange gasket between the header and the head. Start all header bolts (most restricted first) 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 models may require denting the firewall for clearance if the L-4 tube makes contact.
7. Reinstall the power steering ram with a purchased bracket P/N 10961HKR. 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.
8. 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.
9. Replace the spark plugs.
RIGHT SIDE:
1. Remove the stock exhaust manifold and spark plugs.
2. Starting from below, work the header up through the chassis into position over the exhaust ports.
3. Insert the gasket between the header and the head. Start all header bolts (most restricted first) and tighten evenly.
NOTE: 1976 Mavericks / Comets: The vacuum canister must be moved at least 1/2” 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.
4. Tighten all header bolts evenly. Replace the spark plugs. If the collector contacts the emergency brake cable, the bracket must be relocated so the
cable will clear. See Figure A.
5. If equipped with an automatic choke, connect the stock lines from the carburetor to the U-tube on the header.
6. To connect the collector to your stock exhaust system, purchase Hooker header reducer kit P/N 11030HKR.
NOTE: A dual exhaust system can be fabricated using either Hooker Super Competition Turbo Mufflers #21104HKR, 21105HKR, or 21106; Hooker
Competition Turbos #21004HKR, 21005HKR, or 21106HKR; and a universal tailpipe #16215HKR.
7. Connect the battery, start the engine, and check for leaks. Be sure all brake lines, fuel lines, and electrical wires have sufficient clearance. Reroute as
necessary. On manual transmission models, check the clutch for clearance.
When finished, give your vehicle a test drive, checking carefully for any new noises. After several days of driving, retighten all the bolts.
Any questions? Please contact Technical Service: 1-866-GOHOLLEY or 270-781-9741. For online help, please refer to the website: www.holley.com.