DOUG S HEADERS D355-B Full Length Header Instruction Manual
- October 30, 2023
- DOUG S HEADERS
Table of Contents
Installation Instructions & Warranty Information
D355 ~ 1955-57 Chevrolet 265-400 SBC
Fenderwell Exit Long Tube Headers
PERTRONIX PERFORMANCE BRANDS EM ISSIONS CODES
This product is Legal for use. on Pre-Pollutkon Controlled Vehicles. It is
legal for use on all vehicles produced Before Emissions Control Regulations
were Imposed. These are considered Uncontrolled Vehicles and art defined as
follows; 1965 and Older US Manufactured California Certified Vehicles 1967 and
Older US Manufactured Federally Certified Vehicles 1967 and Older Foreign
Manufactured Vehicles
REV 112012
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
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 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
- Remove bolts attaching head pipes stock manifolds, then remove the stock manifolds from the car.
- Remove the Spark Plug Wires and Spark Plugs. Remove the Generator/Alternator.
- Clean the cylinder head exhaust mounting surface.
INSTALLATION
-
If you are running inner fenders you will need to cut them to accommodate these headers. Starting at the back of the cutout for the upper control arm, draw a line angling backwards to about equal with the location of the #3 port on each side, from the front. Go up approx 17” fromtheframerail.Nowgostraightbacktothefirewall.Removethissectionofinnerfender using a Sawzall, Body Saw, Torch, or other method. On 1955 cars you will need to push the inner fender out towards the floor boards.
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Slip the header through the inner fender from the outside in towards the motor. Do this carefully as to not scratch the headers – additional cutting of the inner fenders may be necessary.
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Using the supplied Header bolts and lock washers, slip the gasket in place and start headerboltsateachendoftheflange.Installremainderoftheboltsandtightenfromthe center and working outwards.
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Replace the spark plugs and wires, and the Idler generator / alternator. If the generator was mounted to the left side manifold you will need to purchase brackets # H7606 and H7607.
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Bolt the supplied reducers to the headers using the gaskets, bolts, nuts and washers.
-
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| 1Right side header
2 Header gaskets| 123/8 X 1” header bolts
18 3/8 Lock-washer| 63/8-16 x 1 1/4” Collector Hex head bolts
6 3/8-16 Hex Nuts| 2 Reducers
2 Collector Gaskets| 2 Doug’s stickers
DM GIS II E.t1WItS LIMITED IN tlilt tVI’l
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.
A Per Terformance Brand www.pertronixbrands.com 909 599-5955