Spark Box Rev Chip Selector

Spark Box Rev Chip Selector A REALLY COOL item from our friends at MSD this RPM Module plugs into the side of your 8105 or 8106 Spark Box in the normal place you would place the Single Style Rev Chip and allows you to select your desired RPM limit with the turn of the knob all the way from 6,000 8,200 or 7,600 to 9,800 in 200 RPM increments.