DOUG S HEADERS D356-B Shorty Header Instruction Manual
- October 30, 2023
- DOUG S HEADERS
Table of Contents
DOUG S HEADERS D356-B Shorty
Header
Product Information
The D356 Long Tube Headers are designed for the 1955-57 Chevrolet 265-400 SBC engines. These headers come with header bolts, gaskets, lock-washers, hex nuts, collectors, and Doug’s stickers. The headers are made of high-quality materials that provide durability and long-lasting performance.
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!
Installation Instructions
Disassembly
- Remove the bolts attaching head pipes stock manifolds, then remove the stock manifolds.
- Remove the Oil Dipstick Tube.
- Remove the Spark Plug Wires and Spark Plugs. Remove the Generator/Alternator.
- Clean the cylinder head exhaust mounting surface.
Installation
- Starting on the Driver’s side, slip the header into position from the bottom.
- Using the supplied Header bolts and lock washers, slip the gasket in place and start header bolts at each end of the flange. Install remainder of the bolts and tighten starting from the center and working outwards.
- From below slip the Passenger side header into position.
- Using the supplied Header bolts, slip the gasket in place and start header bolts at each end of the flange. Install remainder of the bolts and tighten starting from the center and working outwards.
- Replace the dipstick tube, generator (bracket part Number H7606/H7607 may be necessary), spark plugs and wires.
- Bolt the supplied reducers to the headers using the gaskets, bolts, nuts and washers.
- Connect the negative battery cable.
Warranty Information
The D356 Long Tube Headers come with a warranty that covers any defects in materials and workmanship. The warranty period starts from the date of purchase and is valid for a specified period. Please refer to the warranty card for more information on the terms and conditions of the warranty.
Parts List
- 1 Left side header
- 1 Right side header
- 2 Header gaskets
- 18 3/8 Lock-washer
- 6 3/8-16 Hex Nuts
- 12 3/8 X 1 header bolts
- 6 3/8-16 x 1 1/4 Collector Hex head bolts
- 2 Collector Gaskets
- 2 Reducers
- 2 Doug’s stickers
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
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.
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
A PerTronix Performance Brand
www.ue1·tI·onixbrands.com
909 599-5955