PERTRONIX D523 Doug’s Header Instruction Manual
- June 9, 2024
- PERTRONIX
Table of Contents
PERTRONIX D523 Doug’s Header
A PerTronix Performance Brand ~
wwwpertronixbrand.com ~ 909 599-5955
Installation Instructions & Warranty Information
D523 ~ 1970-81 Pontiac Firebird 326-455
NOTE: These headers will ONLY work with Ram Air II/IV, Super Duty, HO,
and Edelbrock Performer RPM Heads.
Some Pontiac Heads do not have bolt holes in the end of the manifolds. These
must be present for the headers to seal properly.
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
1970-74 Models
1975-81 Models
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 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.
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
- Unbolt the headpipes from the factory manifolds and move the exhaust out of the way.
- Remove the spark plug wires and spark plugs. Remove the manifolds from the motor.
- Remove the Oil Filter and Housing, the transmission/key interlocking device, the starter, and clutch Linkage.
- If equipped with Air Conditioning, loosen the bracket and slide the compressor out of the way.
- Remove the gaskets and any gasket material or any carbon deposits that remain on the head surface.
INSTALLATION
- Place a jack under the oil pan, with a block of wood to prevent damage to the pan. Loosen the rear transmission mount bolts. Remove the Passenger side motor mount bolt and nut. Raise the motor approximately 1”. Check that the motor mount to cross member bolts are installed with the bolt heads on top and the nuts underneath, if not they will need to be reversed so that the nuts are on the bottom.
- Starting from below, slide the Passenger side header into position.
- Lower the motor and replace the motor mount bolt and tighten.
- Slip the gasket between the header and the head and start all of the supplied header bolts and special lock washers starting with the 4th one from the front as it has restricted clearance. Do NOT tighten.
- With the header loose, install the oil filter housing and the oil filter.
- Tighten the header bolts starting with the 4th bolt, drawing the header up to the head and then tightening the remainder of the bolts.
- On the Driver’s side, check the motor mount to cross member bolts and make sure that they are installed in the same manner as the passenger side as described above. Cut the top of the motor mount bolt so that it is flush with the nut.
- Starting from below, slide the driver’s side header into position.
- With the header loose in the chassis, reinstall the starter motor.
- Slip the gasket between the header and the head, install the rear center port bolt (4th bolt hole from the front) a couple of threads into the cylinder head. Slip the Slotted bolt hole in the header flange over that bolt; slide the header backwards into place. Start all of the supplied header bolts and special lock washers starting with the 4th one from the front as it has restricted clearance.
- Reinstall the Clutch linkage and Transmission/Key interlock.
- Tighten the header bolts starting with the 4th bolt, drawing the header up to the head and then tightening the remainder of the bolts.
- In order to retain the Hot Air to the carburetor, modify the heat stove as shown in Illustration 1.
- Install the supplied reducers using the gaskets and hardware.
- Cut the headpipes to match the reducers if the original exhaust is to be used.
- Reinstall the sparkplugs and plug wires.
- 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
PARTS LIST
- 1 Left Side Header
- 1 Right Side Header
- 2 Header Gaskets
- 2 3 ½” Reducers
- 2 3 ½” Reducer Gaskets
- 12 3/8-16 X 1”, Header Bolts
- 6 3/8-16 Hex Nuts
- 6 3/8-16 X 1 1/4” Collector Hex Head Bolts
- 18 3/8” Internal Lock Washers
- 2 Doug’s Stickers
DOUG’S HEADERS LIMITED WARRANTY
All Doug’s 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.