MSD Ignition Control Module Heat Digital Hei Module With Rev Limiter 83647

MSD Digital GM high-energy modules with rev limiters allow you to adjust the rpm limit between 5,000 and 9,000 rpm. True high-performance modules built for HEI distributors, they produce 50 percent higher coil drive currents than the stock module. This saturates the coil faster, which gives you more spark energy at top speeds. The results are increased horsepower and rpm range, and improved starting. When used with MSD's HEI coil, these plug-in modules create a potent high-energy spark to 9,000 rpm. MSD GM HEI modules replace all 4-pin modules used in HEI distributors with a vacuum advance canister. They can be used with factory, aftermarket, or MSD HEI distributors.