Pypes Performance Exhaust SGF31 User Manual
Pypes Performance Exhaust For the car
SGF10/ SGF11/ SGF13/ SGF17/ SGF18/ SGF20/ SGF31
409 Stainless Steel header/cross-member back exhaust system for
1970-81 GM F/X-bodies
SGF10: 2-1/2” w/ x-pipe, qtr exit tails for optional splitter tips
SGF11: 2-1/2” w/ x-pipe, straight back tails
SGF13: 3” w/ x-pipe, straight back tails
SGF17: 2-1/2” w/ X-Change x-pipe, straight back tails
SGF18: 2-1/2” w/ X-Change x-pipe, qtr exit tails for optional splitters
SGF20: 3” w/ X-Change x-pipe, straight back tails
SGF31: 2-1/2” without x-pipe, straight back tails
Thanks again for purchasing your new 409 stainless steel Pypes Performance Ex-
haust header/cross-member back system. Please be sure to confirm all the compo-
nents in the kit were received in your shipment before beginning installation. These
kits will include (1) X-pipe kit, (2) Mufflers (if purchased), (2) tailpipes, (2) collector
extensions, (2) muffler hangers, (2) tailpipe hangers, (8) clamps, and (1) bonus pack.
If you purchased a kit including mufflers you will see the following notation after the
system number: (S) Street Pro, (R) Race Pro, and (V) Violator. If you find any compo-
nent missing, please contact our office at 800-421-3890 for replacement. Installation
of this kit will require some simple hand tools; box wrenches, deep sockets w/ ratchet,
extension, a saws-all and some penetrating lubricant. For a quicker and tighter instal-
lation, air tools are recommended. Fully welding the system is always recommended
when possible. Technical assistance is available both online at www.pypesexhaust.
com or 800-421-3890. Also, our online Installation Gallery is a great assistant during
your installation, visit www.pypesexhaust.com/pictures.html .
Pypes Performance Exhaust
2705 Clemens Road Bldg 105A Hatfield, PA 19440
800-421-3890 (voice) 267-638-3507 (fax)
www.pypesexhaust.com
(A) Manifold (optional)
(B) Header (optional)
(C) Downpipe
(optional)
(D) Collector Reducer
(optional)
(E) Collector
Extensions
(F) X-pipe Assembly
(G) Mufflers
(H) Tailpipes
(A)
(B)
(C)
(D)
(E)
(F)
(G)
(H)
1. Begin by placing the vehicle on a lift or four jack stands at maximum height to
aid in an easier installation. To help ease the installation, pre-fit all the components into
a complete system on your garage floor, using the diagram provided.
2. Remove the existing exhaust system from the headers or exhaust manifolds
back. You can also remove any hanger mounted to the frame as your new kit includes
factory reproduction hangers.
3. Now install your new components. Begin by test installing your new tailpipes.
These tailpipes have been designed in two pieces to ease installation. The expanded
joint will be just above the rear near the gas tank. The new repro tailpipe hangers will
get mounted in the factory location on the outside of the frame rail just in front of the leaf
spring shackles. Slide the spoon hanger welded to the tailpipe into the hanger just in-
stalled. Next, the over the axle portion of the tailpipe can be installed. Final adjustments
will be done when the entire system is installed. The muffler hangers will get mounted to
the rear seat pans just in front of the rear. On some models, you maybe able to utilize
the original muffler and tailpipe hangers. If you so choose, custom hangers may be
fabricated, let your creativity shine…
4. Now, install the mufflers. The inlet should be closest to the drive shaft and the
outlet should be towards the rockers of the car. The clamp attached to the hanger at the
backside of the muffler will be the only connection clamp used.
5. Next, install the x-pipe. This is where trimming of the tubing may be required
for the optimum fit. Install the rear “X” member into the mufflers first. You are aiming to
have the center “X” land approx 8-12 inches behind the tail shaft of your transmission
and centered under the driveshaft. Also, the center plate on the “X” has an arrow stamp
which must point forward. Trim the rear legs as needed to put your “X” in the proper loca-
tion. Quick tip: If the rear suspension is unloaded, you can push the center “X” up until it
just about touches the drive shaft as it will never hit once t he suspension is loaded. Slide
the front legs into the x-pipe. They should end somewhere close to the humps in your
transmission cross-member. On some applications, the front “X” legs may not be cen-
tered in the humps but line up to your headers or down-pipes. This is fine as the system
will not hang too low. Be extra careful when measuring and cutting. A helpful tip: Line up
the front legs under the center “X” to mark your cut lines making sure to line them up with
you headers or down pipes.
6. Connect the front legs of the x-pipe to the headers (collector reducers) utiliz-
ing the two 1ft collector extension pipes. Trimming the length will be required. Do not
connect the x-pipe directly your headers. If down pipes (see down-pipe instructions) are
used, make sure they end close to the rear side of the transmission cross member. If
they are too long they must be trimmed. Some header applications require custom col-
lectors due to the header not ending square and parallel to the car. For proper system
fit, you collectors must run parallel with your rocker panels.
7. Finish the system by making all your final adjustments to position the x-pipe,
mufflers and tailpipes. Now tighten all the clamps (Warning: tightened clamps will leave
marks in the tubing, making removal or adjustments extremely difficult) or for the best fit
weld all the slip joints. The 409 stainless can be welded with your standard mig welder,
and is highly recommended when possible.
Now it’s time to fire up that muscle car and enjoy your
new Pypes Performance Exhaust.