MSD 84697 Installation

MSD Billet Crank Trigger Distributors

PN 84697, PN 8558 and PN 84698 (GM DRCE Block)

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Note: Read these instructions completely before attempting the installation.

Parts Included:

1 - MSD Distributor Assembly
2 - O-Rings
1 - Tube of Gear Lubricant

Replacement Parts:

Rotor and Base, PN 8457
Cap, PN 8408
GM DRCE Bronze Gear, PN 84711

WARNING: During installation, disconnect the battery cables. When disconnecting the cables,

always remove the Negative cable first and install it last.

1 - Gasket
1 - Rotor Phasing Tech Brief

Chevrolet Bronze Gear:
Standard (0.500" ID), PN 8471
Oversized (+0.006"), PN 8472

Note: A Crank Trigger must be used with this distributor.
An MSD Billet Hold-Down Clamp, PN 8110, is recommended.

REMOVING THE DISTRIBUTOR

1. Remove the existing distributor cap without disconnecting any
of the spark plug wires.

2. With the cap off, rotate the engine or until the rotor is aimed at a
fixed point on the engine or firewall. Note this position by making
a mark (Figure 1).

3. Place the distributor cap back on and note which plug wire the
rotor is pointing to. MARK THE SPARK PLUG WIRES and remove
the distributor cap.

4. Loosen the distributor hold-down clamp and slide the clamp
out of the way.

5. Lift the distributor out of the engine. Note that the rotor rotates
as you lift the distributor out. This is due to the helical cut gear
and should be taken into consideration when installing a new
distributor.

Figure 1 Marking the Rotor Location.

M S D   •   W W W . M S D P E R F O R M A N C E . C O M   •   ( 9 1 5 )   8 5 7 - 5 2 0 0   •   F A X   ( 9 1 5 )   8 5 7 - 3 3 4 4

2 INSTALLATION INSTRUCTIONS

PREPARING THE DISTRIBUTOR

O-RING SEALS

The MSD Billet Distributor features two O-ring
grooves in the bottom lands of the housing to
seal the oil gallery. These O-rings should only
be installed if the block has been modified as
shown in Figure 2.

ADJUSTABLE SLIP COLLAR

The MSD PN 8558, Distributor features an adjustable slip collar. This collar provides an adjustment
to accomodate variations in block height, modified intakes or heads. It is recommended to check the
slip collar setting before installation. MSD offers a special tool, the 3-In-1 Distributor Set Up Tool, PN
8599, to make these adjustments accurately. If the tool is not available, follow this procedure.

1. Loosen the slip collar and insert the distributor into the engine until it bottoms out against the oil
pump drive.

2. After it bottoms out, raise the distributor 0.010" - 0.030" then slide the slip collar down into the
position and tighten it.

Figure 2 Modified Block to Accept the O-Ring Seals.

CHECKING THE OIL PUMP TO DISTRIBUTOR SHAFT OVERLAP

The proper overlap between the distributor shaft and the oil pump shaft is very important. The tongue
of the distributor shaft should fit into the groove of the oil pump shaft by at least 1/4". To check this:

1. Measure the distance between the base of the slip collar to the tip of the distributor shaft (Figure 3).

2. Using a straight edge, measure the distance from the intake manifold distributor flange to the top
of the oil pump intermediate shaft (Figure 3).

3. Take the two measurements and subtract
them. The difference is the overlap. If
there is not enough clearance or too much
clearance, a different oil pump shaft is

required.

CHECKING GEAR MESH

It is recommended to check for proper gear
mesh between the cam gear and distributor
gear. To do this, coat the distributor gear
with moly grease and install the distributor.
Next, crank the engine over several times.
Before pulling the distributor out, make sure
the rotor is in the position that lines up with
the original removal mark. Then pull the
distributor out and inspect the gear pattern
shown on the grease. The proper mesh will
leave an even pattern in the middle of the
gear. Adjust the slip collar to obtain the correct mesh.

M S D   •   W W W . M S D P E R F O R M A N C E . C O M   •   ( 9 1 5 )   8 5 7 - 5 2 0 0   •   F A X   ( 9 1 5 )   8 5 7 - 3 3 4 4

Figure 3 Checking Oil Pump Shaft to the Distributor Shaft Overlay.