409S
®
Stainless Steel
WARNING: The product accompanying this document is legal only for off-highway use (except in California or
states that have adopted California emission standards), racing use or for use on pre-emission-controlled motor
vehicles/motor vehicle engines (pre-1966 domestic vehicles certified to California standards, pre-1968 domestic
vehicles certified to federal standards and all pre-1968 foreign vehicles), per the manufacturer’s application guide.
Note: I
nstallation of this product requires an adequate work space, general mechanic’s tools, general
mechanical “know how” and a reasonable level of experience. Most auto enthusiasts with these resources will
have little difficulty installing these headers. However, you should carefully read these instructions before
attempting to install these headers. If in doubt, consult a professional mechanic. (Better to do it now than to get
stuck halfway through the installation.)
Check to make sure that you have received the proper parts for your installation. 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. If you are not comfortable with welding operations, we recommend that you contact a
professional exhaust system specialist to install your new headers.
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.
The purchaser is responsible for following all installation instructions and safety guidelines supplied with your
new Flowmaster Performance Exhaust Product. Flowmaster Performance exhaust assumes no responsibility
for damages resulting from improper operation, misuse, abuse, or lack of reasonable care, or any problems
resulting from incompatibility with other manufacturer’s products.
Flowmaster uses sealing beads on its headers. We have found that when installed correctly, the raised bead
around each port increases the pressure exerted on the gasket directly adjacent to the port and effectively
prevents leaking gaskets. It is normal for the flange to be raised off the cylinder head the thickness of the
sealing bead. It is important when installing the header to install all bolts loosely, and then tighten evenly to
ensure the flat installation of the flange. The torque sequence from one flange to another will vary, but
generally every bolt on a header should be first fit snug, starting from the inside of the flange working out,
alternating from top to bottom so that the bolt connects the flange to the manifold to the point where they barely
touch. Second, using the same inside-out pattern, tighten each bolt until finished. This method will help prevent
leakage and will give the user the best possible performance out of their new set of headers.
Header Installation Instructions:
Part Number: 814110
1965-89 Chevrolet Passenger Car & Wagon
1967-81 Camaro, 1964-87 Chevelle, El Camino
1970-87 Monte Carlo, 1968-79 Nova
