I have the Simultaneously Firing Dual Ignition system by NSI. One of the six-post isolation modules failed causing engine to run very rough on B-only. A-only or both works fine. Appears that two of the four plugs quit on B-only. The isolation modules are installed between the four coils and the plugs. In the original NSI installation manual the part number is 101-17200-00. Hoping to find someone who has one or two of these for sale. This a wasted spark system so the current flows into two plugs and from two plugs. So half the diodes in the isolation modules are reversed. Thus I believe the MSD coil selector (8210) won't work. Alternatively, any suggestions regarding replacing the ignition? Does a dual ignition system with a single alternator, battery and set of plugs provide much additional safety?