MSD 8428 GM HEI Weight & Spring Kit Installation User Manual
Advance kit, gm hei distributors
Advance Kit, GM HEI Distributors
PN 8428
WARNING: When installing the Advance Kit, disconnect the battery cables. When disconnect-
ing, always remove the negative cable first and install it last.
Parts Included:
2 - Blue Weight Bushings
2 - Black Weight Bushings
2 - Red Weight Bushings
Figure 1 Spring Rate Timing Advance.
Note: This kit is designed for stock style GM HEI Distributors. It is not for use with MSD’s Pro-Billet
HEI, PN 8365.
3 - Sets of Advance Springs
2 - Weights
1 - Center Plate
Figure 2 Installing the Advance Kit.
ADVANCE SPRINGS
This kit provides three different advance springs; light, medium and heavy. These determine how
quick the centrifugal advance comes in as the weights overcome the spring tension. The chart in
Figure 1 shows the approximate advance of the spring combinations.
500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000
8
12
16
20
22
24
24
24
24
24
24
24
24
24
0
8
10
14
16
18
20
20
22
22
22
22
22
22
0
0
8
10
12
12
14
14
16
16
18
18
18
18
LIGHT SPRING
MED. SPRING
HEAVY SPRING
ADVANCE CURVE FOR THE PN 8428 GM HEI WEIGHT AND SPRING KIT
1. Once you’ve selected the springs for your
distributor, remove the cap and rotor.
2. Use a pair of needlenose pliers and remove
the original springs. Note the fit and direction
of the weights and center plate (Figure 2).
3. If equipped, remove the E-clips that secure
the weights. Remove the weights and center
plate.
4. Install the supplied bushings to the weights.
Three sets are supplied. Use the set that fits
snug over the weight pin.
5. Install the center plate followed by the weights.
A small dot of lubricant on the bottom of the
weights will ensure smooth operation.
Note: Figure 2 shows a clockwise rotating en-
gine. For CCW, the weights and center
plate are reversed.
CENTER
PLATE
WEIGHT
BUSHING
WEIGHTS
WEIGHT
BUSHING
6. Install the springs making sure they are positioned in the spring grooves of the pins. Install the
rotor and cap.
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