Owners manual

2452HKR (black paint), 2452-1HKR (silver ceramic), 2452-2HKR (stainless),
2452-3HKR (Darkside black ceramic), and 2452-4HKR (Titanium Ceramic)
COMPETITION HEADERS
69-91 Blazer, Suburban/Jimmy, Carryall, Yukon, & 1-Ton Crew Cab (2WD) 265-400
63-87 1/2 Ton, 3/4 Ton, & 1 Ton Truck (2WD) 265-400
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 cast iron exhaust manifolds or old headers to break in new engines to avoid coating damage. Please
call tech service at 270-781-9741 for additional information regarding ceramic-coated exhaust products.
NOTE: Available with fittings to accommodate air injection manifold – P/N 02452HKR. This P/N will fit 1969-86 model years only.
NOTE: Reducers available with oxygen sensor on 1980 and later models: 2 1/2” bolt-on P/N 11045HKR or 3” bolt-on P/N 11046HKR.
NOTE: Will not fit angle plug heads.
NOTE: Aluminized dual exhaust kits that bolt to the 2452HKR is available under P/N 16523HKR.
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 prior to installing headers, take the time to make a careful and complete
inspection of both engine and transmission mounts. Replace them if they look worn or damaged, otherwise this may affect the
header fitting into your vehicle properly.
INSTALLATION PROCEDURE: PLEASE READ THOROUGHLY & CAREFULLY
LEFT SIDE
1. Disconnect the battery cable to prevent damage to the electrical systems.
2. Unbolt the headpipes (both sides) and remove from the truck.
3. Remove the stock exhaust manifold, oil filter, spark plugs, dipstick and dipstick tube. Manual transmission models will need to remove the
clutch linkage.
4. If the alternator/generator or air conditioning compressor is mounted on the head, remove it.
5. Starting from below, work the header up through the chassis into position over the exhaust ports. Insert the gasket between the head and
the flange. Start all header bolts (most restricted first) and tighten evenly.
6. Replace the oil filter, spark plugs, dipstick, dipstick tube, and clutch linkage (if removed).
NOTE: A) 1967 models – Modify the clutch linkage (Figure A).
B) Late models – May require shift linkage modifications for adequate header clearance (Figure B).
C) Models with generator/alternator on the left side must purchase Hooker bracket P/N 10928HKR (Figure C).
D) Models with power steering – May require the installation of the supplied spacer for remounting the pump bracket (Figure D).
E) To replace the air conditioning compressor, use the supplied bracket (Figure E).
RIGHT SIDE
1. Remove the stock exhaust manifold, spark plugs, and starter.
2. If the generator/alternator and/or air conditioning compressor are mounted on the head, remove them.
3. Starting from below, work the header up through the chassis into position over the exhaust ports. Insert the gasket between the flange and
the head. Start one bolt to hold in place.
4. With the header loose, install the starter. Start the remaining header bolts (most restricted first) and tighten evenly.
5. Replace the spark plugs. If the generator/alternator and/or air conditioning compressor was removed, use the purchased bracket to
remount (Figures C and/or E).
6. To connect the collector to your stock exhaust system, purchase the Hooker reducer kit P/N 11026HKR. Position the gasket and the bolt
the reducer to the collector. Cut the head pipe to the correct length and weld the reducer.
NOTE: Finish the performance job your headers started by adding a Hooker competition dual exhaust system. Large 2 1/4” diameter tubing is
mandrel bent, not press bent. Mandrel bending maintains a consistent inside diameter form maximum flow; press bending will crush
the pipe, easily reducing volume by more than 10%. Our dual exhaust system is perfect when used in conjunction with Hooker Super
Competition Turbo 21105HKR or Hooker Competition Turbo 21005HKR. Purchase duel exhaust no. 16522HKR: 1963-72 models.
Purchase dual exhaust no. 16523HKR: 1973-87 models.
7. Connect the battery, start the engine, and check for leaks. Be sure that all brake lines, fuel lines, and electrical wires have sufficient
clearance. Reroute, as necessary.
8. When finished, give your car a test drive, checking carefully for any new noises. After several days of driving, retighten all the bolts.