A stock HEI distributor cap's carbon rotor button carries high resistance, which can build up heat and melt the cap when the high voltage of an MSD 7-Series ignition is added. This low resistance bushing passes secondary voltage from the cap to the rotor without that excessive heat buildup.
Specifications:
- Distributor Type: HEI
- Category: Ignition
- Part Type: Distributor Bushing
- Product Type: Distributors and Components
- Sub Category: Bushings
- Warranty: Manufacturer's Limited 1 Year Warranty
- Part Number: 8412
FAQ
Why is the MSD 8412 bushing needed with a 7-Series ignition?
A stock HEI cap's carbon rotor button has high resistance, which can build heat and melt the cap when paired with the high voltage of a 7-Series ignition; this bushing prevents that.
What does this bushing do?
It passes secondary voltage from the distributor cap to the rotor without excessive heat buildup.
What distributors is this bushing for?
HEI distributors.

