MSD Pro-Billet Ready-to-Run Distributor

Chevrolet V8, PN 8360/83603

Chevrolet 348, 409, PN 8393

Chevrolet 409 Aluminum Block Only, PN 83931

WARNING: Before installing the MSD Ready to Run Distributor, disconnect the battery cables. When

disconnecting the battery cables, always remove the Negative (-) cable first and install it last.

Parts Included:

1 - Pro-Billet Distributor

1 - Rotor, PN 8467

1 - Distributor Cap, Red PN 8433 or Black PN 84333

1 - Wire Retainer

2 - 1.5" Self Tapping Screws

2 - 10-32 x 3/4" Socket Head Screws

Note: The terminals of this Ready-to-Run Distributor require spark plug style terminals. You may need to

changetheterminalsandbootsofyourwires.MSDofferstwokits,PN8849 or PN 8848 that are supplied

with nine boots and terminals.

Note: If the gear is ever replaced, MSD Gear (PN 8531) is required for replacement due to the .500"

diameter shaft.

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 approximately 12° 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.

RPM LIMIT AND TACHOMETER INFORMATION

Tach Signal: The Ready-to-Run Distributor features a Gray Tach Output wire which provides a clean signal

for most tachometers and even some aftermarket fuel injection systems. The signal output

is a 12 volt square wave, 20° duty cycle. This wire is also responsible for programming the

built-in rev limiter.

1 - Advance Kit

1 - 3-Pin Harness

1 - Gasket

1 - Tube of Gear Lubricant

2 - O-Rings

1 - Vacuum Advance Lock-Out Kit

1 - Gray Tach Jumper

ONLINE PRODUCT REGISTRATION: Register your MSD product online. Registering your product

will help if there is ever a warranty issue with your product and helps the MSD R&D team create

new products that you ask for! Go to www.msdperformance.com/registration.