The standard tach drive for MSD Tach Drvie Distributors is a 3/16'' tang drive cable. In most cases this type drive will work, but thse who require the 0.104'' square drive (Corvette style), MSD offers a Tang to Square Drive Adapter to fit all MSD Tach Drive Distributor assemblies.

Note: This is not included with each MSD Tach Drive Distributor.