Owners manual

IMPORTANT: Due to the number of applications and years that the LT-1 Distributor is used on, it is highly
recommended to have the Service Manual for your vehicle during this installation.
IMPORTANT NOTES BEFORE INSTALLATION
Throughout its course, the GM LT-1engine used two different drive mechanisms to connect the cam
to the distributor. Figure 1 shows the drive for the MSD PN 8381 Distributor. This design is used in
the early model distributors. Make sure this is correct for your application.
Before removing the distributor it is recommended to mark the location of the rotor. This is to ensure
that the distributor and cam are indexed correctly prior to reassembly.
Be sure that the O-ring between the distributor cap and the housing is in place before installing the
cap. The O-ring must be stretched out, then installed onto the housing. It will shrink back to size.
TIMING INFORMATION
Since the timing of the MSD Pro-Billet Distributor can be adjusted, it is recommended that a timing indica-
tor and mark be fabricated prior to installing the distributor. This way, the timing can be recorded so the
MSD Distributor can be set to the same amount. From the factory, the MSD Distributor is set to the factory
specs (two turns out).
The MSD Distributor can alter the timing +/-7°. The ad-
justing screw has a soft Loctite compound applied to it
for a seal (Figure 2). Repeated adjustments may loosen
the screw. If this occurs, remove the screw and apply
Blue Loctite
®
to the threads. The screw can safely be
removed from the distributor.
Too much advance may cause detonation resulting in
the ECU retarding the timing through the engine’s knock
sensor.
When adjusting the timing, take note that the ECU varies
the timing at an idle. It is recommended to bring the en-
gine rpm up to 1,500 - 2,000 when setting the timing.
MSD Pro-Billet LT-1 Distributor
'93-'94 F-Body, '92-'94 Corvette, '92-'94 Full Size
PN 8381
Parts Included:
1 - Distributor
1 - Cap
1 - Rotor
1 - Isolator
2 - Rotor Screws
1 - O-ring
3 - 1/4-20 x 2" Socket Head Cap Screws
5 - 8-32 x 0.5" Phillips Screws
1 - Vacuum Line Assembly
1 - Removal Tool
Figure 2 Adjusting the Timing.
Figure 1 The Drive Mechanism of the PN 8381 Distributor.
TIMING
ADJUSTER
CAMSHAFT
STOCK DISTRIBUTOR
INDEX
FLAT
SPOT
INDEX
MSD • WWW.MSDPERFORMANCE.COM • [phone] • FAX [phone]