If the new pro-cap doesn't work on your application, these MSD cap-a-dapt will do the trick. The MSD cap-a-dapt adapts a large, Ford style cap onto your MSD distributor. The rotor is injection molded out of Rynite?.
MSD 8142 Coil for MSD Pro Mag 44 Amp Red
MSD Tachometer Adapter for Dodge Daytona 1991-1993
MSD 5594 Distributor for 1986-1993 Ford Mustang 5.0L
MSD Tachometer Adapter for Dodge D150 1991-1993
MSD Tachometer Adapter for Dodge Dakota 1987-2003
