DOUG S HEADERS D590-B Full Length Header Instruction Manual

October 30, 2023
DOUG S HEADERS

DOUG S HEADERS Logo HEADERS D590-B Full Length Header
Instruction Manual

DOUG S HEADERS D590-B Full Length Header -

D590-B Full Length Header

Petron Performance Brand www.pertronixbrands.com 909 599-5955
Installation Instructions & Warranty Information
D590 ~ 1967-72 Pontiac GTO 326-455
68-72 LeMans/Tempest 326-455
Long Tube Headers
DOUG S HEADERS D590-B Full Length Header - IconPERTRONIX PERFORMANCE BRANDS EMISSIONS CODES
This Product Is considered a Replacement Part per CARB and EPA regulations for emissions compliance and Is legal for sale and use on specified vehicles in all 50 states as stated In Manufacturer’s Application Guide and Installation Instructions.
REV 1-1022

PLEASE READ BEFORE PROCEEDING

PerTroniethanks 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 Petromax 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

  1. Disconnect the headpoles from the exhaust manifolds and move them out of the way.
  2. If you are planning on reusing the headpoles, cut them approximately where the header Electors will exit. If you are not reusing them, remove completely.
  3. Remove the spark plug wires and spark plugs.
  4. 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  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.
  5. Remove the gaskets and any gasket material or any carbon deposits that remain on the head surface.
  6. Remove the Starter motor, Clutch Linkage, Dipstick tube (if on the right side) and oil filter and it 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 headpoles to the reducers or fabricate new exhaust.
  17. Connect the negative battery cable.

DOUG S HEADERS D590-B Full Length Header - Fig

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
2 Header gaskets
12 Lock-washer
6 3/8-16 Hex Nuts
2 3” Reducer gaskets
1 Oil Filter Adaptor Gasket| 1Right side header
12 3/8-16 X 1”, header bolts
63/8-16 x 1 1/4” Collector Hex head bolts
63/8” Lock washers
23” Reducers
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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. Petromax reserves the right to replace or repair the alleged defective part and return the part freight collect.

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