DOUG S HEADERS D305 1 5/8 Inch 4-Tube Shorty Header Chevrolet Instruction Manual
- June 9, 2024
- DOUG S HEADERS
Table of Contents
DOUG S HEADERS D305 1 5/8 Inch 4-Tube Shorty Header Chevrolet
Installation Instructions & Warranty Information
D305 ~ Stick Shift ONLY
1967-69 Camaro, 1968-79 Nova, 1967-69 Firebird with SBC
Mid Length Headers
PERTRONIX PERFORMANCE BRANDS EMISSIONS CODES
This product Is Legal for use on Pre-Pollution Controlled Vehicles. It is
legal for use on all vehicles produced Before Emissions Control Regulations
were imposed. These are considered Uncontrolled Vehicles and are defined as
follows; 1965 and Older US Manufactured California Certified Vehicles 1967 and
Older US Manufactured Federally Certified Vahines 1967 and Older Foreign
Manufactured Vehicles REVJ/202
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/2022
PLEASE READ BEFORE PROCEEDING
PerTronix thanks you for choosing a Doug’s Headers Product. To realize the potential of Doug’s Headers 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. Many factors affect he installation of exhaust headers, including whom 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, dean the sealing surface on the head of any old
gasket debris or carbon build up.
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!
DISASSEMBLY
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Remove and mark all spark plug wires and then remove all spark plugs.
NOTE: Grasp spark plug boot, not the wire, and use a twisting motion while pulling the wire from the plug. -
Disconnect the head pipes from the exhaust manifolds and remove the manifolds.
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Remove the alternator, dipstick, dipstick tube, and clutch linkage. Remove the starter. On late model cars, remove the power steering bracket.
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On cars equipped with air conditioning, unbolt the compressor and lay aside.
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Some models may require the floor board heat shield removal for adequate clearance.
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Early models will require a conversion screw-on type filter.
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The clutch linkage may need to be modified as in Illustration A.
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Models with generator/alternator on the left side may need to purchase Doug’s brackets H7606 and H7607. See Illustration B.
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On some year models, it will be necessary to remove the two struts that bolt to the sub-frame.
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Replace the spark plugs finger tight so debris will not get into the cylinders during the cleaning operation.
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Remove any gasket material or any carbon deposits that remain on the head surface.
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After cleaning is complete remove the spark plugs again.
ASSEMBLY
- It may be necessary to lift the Driver’s side of the engine about 1” by removing the motor mount bolt on either side. Use a board between the pan and jack.
- Install the headers from the bottom of the vehicle. Slide the headers into place with the gasket and install a bolt at either end of the header to hold them in place.
- Lower the motor, replace the motor mount bolts and check for header clearance.
- Using the supplied header bolts and lock-washers, apply a small amount of anti-seize to the bolts and start the most restrictive bolts first. Tighten evenly from the center outwards
- Replace the clutch linkage, oil filter, dipstick tube and dipstick and alternator.
- On late model cars with power steering, use the spacer provided and the long bolt from the stock exhaust manifold to remount the power steering. See Illustration C.
- Replace the starter and connect the wires. Reroute the wires as needed for clearance.
- Install the spark plugs and connect the wires to the proper plug. It may be necessary to reroute wires to clear the headers.
- Install the reducers and determine the connection to the exhaust system.
- Weld the reducers to the exhaust system and install them onto the headers utilizing the gaskets and bolts supplied.
- Check to make sure that all the wiring, brake lines, hoses, etc. are clear of the headers or any exhaust component.
- Make sure all necessary brackets and accessories have been replaced and secured.
- Depending on which A/C bracket is fitted, it may require modification. See Illustration D
- Connect the battery cable.
IMPORTANT CHECK LIST
- Be sure that all brake lines, transmission lines, and fuel lines are clear of headers and/or connector pepos.
- All spark plug wires. battery cables, or other electrical components should be clear of headers and for 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
Parts List
- 1 Left side header
- 2 Header gasket
- 12 Bolt, header, flanged, 3/8”-16 x 1”
- 20 Lock-washer, 3/8”
- 6 Nut, hex, 3/8”-16
- 1 Right side header
- 2 Reducer gasket
- 2 Bolt, header, flanged, 3/8” -16 x ¾”
- 6 Hex head cap screw, 3/8”-16 x 1-1/4”
DOUGS IIEADES 1IWITED WARRANTY
All Doug’s Headers and Exhaust products are guaranteed, to the original purchaser, to be free of defects in material and workmanship for anew 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. PerTronlx reserves the rights to replace or repair the alleged defect live part and return the part freight collect.
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