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HOW TO MEASURE YOUR BOAT FOR EXHAUST SYSTEMS
The following diagrams illustrate the measurements we will need from you when ordering
thru-hull exhaust components such as diverters or complete muffler systems. To make ordering
easier, also have the following information ready when you fill out the form: Your boat year,
make and model, engine size, (Mercury, Volvo, OMC), drive model and is it an EFI or
carbureted engine.
If you have any questions please call a  sales representative 1-888-426-2841

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Under Swim Platform Applications

For boats with built in or bolt-on swim platforms that DO NOT currently have thru-hull exhaust,
the following measurements will determine if there is enough space under the swim platform to
install a standard system or if a custom system will be required.

A. Distance measured from the vertical center line of the drive (gimbal) housing to the upper
corner of the drive cavity.
For bolt-on swim platforms, measure the distance to the first mounting bracket (See diagram
below).
B. Distance measured from the top of the drive (gimbal) housing to the underside of the swim
platform (See diagram
below).
* Also applies to Twin Engine applications.
NOTE: When measuring distances on a built in swim platform, measure to the tangent of the
radius as shown in the illustration.
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Location of Existing Exhaust Holes
For boats that currently DO HAVE thru-hull exhaust, the following measurements will determine if
the exhaust holes are in the standard location for your particular motor or if a custom system will
be needed to meet the existing exhaust holes
(See diagram below).
X. Distance measured from the vertical center line of the drive (gimbal) housing to the vertical
center line of the exhaust hole.
Y. Distance measured from the top of the drive (gimbal) housing to the horizontal center line of
the exhaust hole (See diagram below).
* Also applies to Twin Engine applications.
X & Y Standard hole locations are as follows. (merc)
(305, 350 6.2L & 383) X = 12-1/8"   Y = 2-1/2" (+/- 1/4)

(454-502)                     X = 13 5/8"   Y = 3"  (+/- 1/4)
We will need the A & B measurements (see below) of your boat on the
following form. Or The (X & Y if you have thru transom exhaust
holes now). Also check for spacer blocks between your manifold
and the exhaust elbow/riser.
(if you have them, what size 3" or 6" ?)
You can print this page then get your measurements,or if you
already have them click the button to continue.                     
If your looking for side exit exhaust, put 001 in the A & B
measurement fields.
This info is required to insure a proper fit for your boat!
Measure the distances for A & B as shown above, if you come up with the
following dimensions (see below) or more, the standard system will work.
If you come up with any less, you will need a custom system. Click "continue"
to get a quote for a custom system.

MerCruiser 305, 350, 5.7L, 377, 6.2L, 383.  A = 15 1/8" or more (Good)
                                                                            B =   5 1/2" or more (Good)

MerCruiser 454 & 502 (not 496)                    A = 16 5/8" or more (Good)
                                                                            B =   6"       or more (Good)
See figures at bottom of page.