MSD designed these Coils by combining our Blaster Coil experience with E-core coil efficiency. Each coil has a unique turns ratio plus there is lower primary resistance than the stock coil. This all amounts to a bolt-in replacement coil that produces more output voltage. The Coils will work with stock ignition systems as well as MSD equipped cars and trucks.Features:- Direct performance replacement for GM 2 Tower coils used from the mid 1980s to late 1990s- 80:1 turns ratio and lower primary resistance produce high voltage output- Works with stock ignition as well as MSD Ignitions- CARB E.O. ApprovedSpecifications:Brand MSDEmission Code 1Inductance 4.2mHMaximum voltage 40,000 VoltsPeak current N/APrimary resistance .35 OHMsSecondary resistance 7.8K OHMsSpark duration N/ATurns ratio 80:1Weight N/A