MSD Digital 6AL Ignition Controllers # MSD6425MSD Digital 6AL Ignition Controllers # MSD6425 Ignition Box, MSD 6AL, Digital CD, with Rev Limiter, Red, Each Ignition Box Output: Capacitive discharge Circuitry: Digital Rev Limiter: Yes Timing Retard: None Data Acquisition: No CD Voltage Output to Coil: 520 540 V Current Draw: 0. 7 amps per 1,000 rpm Spark Output (millijoules): 135 145 Millijoules Minimum Operating Voltage: 12 V Maximum Operating Voltage: 15 V Length (in): 8. 000 in. Height (in): 2.