PerTronix D590 User Manual

Corporate Office: PerTronix Inc. 440 E. Arrow Highway, San Dimas, California 91773 * Phone [phone] * FAX [phone] * www.dougsheaders.com

HEADER INSTALLATION INSTRUCTIONS

PART NUMBER D590

Application: 1967-72 Pontiac GTO 326-455

68-72 Pontiac LeMans/Tempest 326-455

PerTronix©

to realize the full potential of our good fit, please read and understand these instructions completely prior to starting work.
Check to make sure you received the proper parts for your application. The header number will be stamped on the engine

flange. If you are unsure you have received the proper parts call before you start work.
Be sure to work safe! Whenever you work under the vehicle be sure that it is located on level, solid ground and is supported

by adequate safety stands! Remember: Hot asphalt will not support most jack stands!
Many factors affect the installation of headers, some of which are broken or aftermarket motor mounts, accidents that impact the

configuration of the frame, and/or the installation of different engines or aftermarket cylinder heads.
Attention Customers breaking in new engines: Due to the extreme heat generated during the break-in process, the

appearance of the ceramic coating may be altered in certain areas. The protection characteristics and thermal barrier properties
of the coating is never compromised. It is recommended that a cast iron manifold or old set of headers be used for this process.

Notice: The coating of these headers can be marred or scratched during installation. If the header needs to be returned and is
damaged, you will be charged for recoat.

thanks you for choosing

DOUG’S HEADERS

, the best fitting, highest quality header on the market. In order

DISASSEMBLY

1. Disconnect the negative battery cable from the battery.

2. If a car lift is not available, raise the vehicle 3 feet or higher and support with adequate
safety stands. Make sure the vehicle is on a flat solid surface and is stable.

3. Disconnect the headpipes from the exhaust manifolds and move them out of the way.

4. If you are planning on reusing the headpipes, cut them approximately where the header
collectors will exit. If you are not reusing them, remove completely

5. Remove the spark plug wires and spark plugs.

6. Remove the 6 manifold bolts from each manifold and remove the manifolds from the
car. Some Engines only have 4 manifold bolts from the factory. It is highly
recommended that the other two bolt holes on each head be drilled and tapped for
bolts, otherwise header leaks will most assuredly occur and there is no warranty
against this.

7. Remove the gaskets and any gasket material or any carbon deposits that remain on the
head surface. The use of a gasket removal agent will ease the removal of any gasket
material. Use care not to get debris into ports or spark plug holes

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8. Remove the Starter motor, Clutch Linkage, Dipstick tube (if on the right side) and oil
filter and oil filter adaptor (place a drain pan under the filter area).

INSTALLATION

1. Starting on the passenger side. Remove the center bolt from the pass side motor
mount.

2. Pace a flat board between the oil pan and a floor jack and lift the passenger side of the
motor approximately 2”.

3. Working from below, slip the header carefully into position. Carefully lower the motor
while holding the header from getting damaged by the motor.

4. Reinstall and tighten the motor mount bolt. If the motor mount had a safety tab in the
center this will have to be discarded.

5. Slip the gasket between the motor and the header and install the supplied header bolts
and star washers STARTING with the 4th one from the front first.

6. Once all the bolts are started tighten evenly working from the center outwards until all
are tight.

7. Reinstall the Oil filter adaptor, oil filter (Re-check the oil level), & Dipstick tube.

8. Reinstall the spark plugs and wires on this side.

9. Working from below, slip the driver’s side header carefully into position.

10. On some vehicles, the brake Distribution Block, MAY interfere with the L4 header tube.
If this is the case, you will need to relocate the block and brake lines upward by about
an inch or so. Failure to do so will result in the header not fitting.

11. Slip the gasket between the motor and the header and install the header bolts
STARTING with the 4th one from the front first.

12. Once all the bolts are started tighten evenly working from the center outwards until all
are tight.

13. Reinstall the starter motor; make sure that the wiring does not come in contact with the
header.

14. Reinstall the clutch linkage.

15. Reinstall the spark plugs and wires.

16. Bolt the supplied reducers to the collectors using the bolts, lock washers and nuts.
Weld the existing headpipes to the reducers or fabricate new exhaust.

17. Connect the negative battery cable.

IMPORTANT CHECK LIST

Be sure that all brake 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.

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