MSD Distributor Bushing 8412; Low Resistance HEI Bushing for GM

With the introduction of our 20 Amp extreme HEI module, we needed an HEI cap and rotor that could withstand the high output. The answer was to mold our own HEI cap, rotor and coil cover. The cap and rotor will fit our HEI Pro-Billet distributor, PN 8365, plus will work on stock applications. The carbon rotor button in a stock HEI distributor cap has very high resistance. When the high voltage of an MSD 7 series ignition is added, this resistance builds up heat and can actually melt the distributor cap. The solution to this problem is the use of the MSD low resistance HEI bushing which will pass the secondary voltage from the distributor cap to the rotor without excessive heat buildup.