MSD 8389 Chrysler 392 Ready to Run Distributor Installation - Manual

M S D I G N I T I O N
• W W W . M S D I G N I T I O N . C O M • ( 9 1 5 ) 8 5 7 - 5 2 0 0 • FA X ( 9 1 5 ) 8 5 7 - 3 3 4 4
WARNING: Before installing the MSD Distributor, disconnect the battery cables. When disconnect-
ing the battery cables, always remove the Negative (-) cable first and install it last.
MSD Pro-Billet Ready-to-Run
Chrysler Distributor
PN 8391 - 331/354 Early Hemi
PN 8389 - 392 Early Hemi
1 - Advance Kit
1 - O-Ring
1 - Vacuum Advance Lock-Out Kit
1 - 3-Pin Wiring Harness
1 - Gray Tach Jumper
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Important: Read these instructions before attempting the installation.
Parts Included:
1 - Pro-Billet Distributor
1 - Rotor, PN 8467
1 - Distributor Cap, PN 8433
1 - Wire Retainer
2 - 1.5" Self Tapping Screws
2 - 10-32 x 3/4" Socket Head Screws
Note: The terminals of this Distributor require spark plug style terminals. You may need to change the
terminals and boots of your wires. MSD offers two kits, PN 8849 or PN 8848 that are supplied with
nine boots and terminals.
TIMING FUNCTIONS
Before continuing with the installation, here are a few definitions you should be aware of:
Initial Timing: This is the base timing (also referred to as idle timing) of the engine before the
centrifugal advance begins.
Centrifugal Advance: The centrifugal (or mechanical) advance mechanism is made up of weights,
springs, advance cams, and an advance stop bushing. The amount and rate of advance that your
distributor is capable of is determined by the centrifugal timing. If you ever wish to lock out the
centrifugal advance, refer to the centrifugal advance section.
Total Timing: This is the total of the initial timing plus the centrifugal advance added together.
Example: 10° Initial + 25° centrifugal = 35° Total Timing. (When checking Total timing, disconnect
and cap the vacuum canister and plug the vacuum line.)
Vacuum Advance: The vacuum advance will advance the timing up to 10° during partial throttle
driving (with 15 lbs of vacuum). The vacuum line should be routed to a ported vacuum outlet above
the throttle plates.
Note: MSD Distributors are supplied with the heavy (slow) advance springs and the 21° stop bushing
installed. This is to prevent detonation in certain applications. Review the information on pages
2-4 to determine the best advance curve for your application.