At least five ignition modules with slightly different advance curves are needed to obtain the data points to select the optimum ignition timing. The old 360 degree boxes could not be reprogrammed so I ordered five new ones. They are a Stage 3 curve that has worked well in the past with -4, -2, 0, +2, and +4 degree retards and advances. The rev limiter is at 9,000 rpm now. It might be changed to 9,500 or 10,000rpm once all reliability issues are resolved such as rod big end shell fatigue.
The plugs that seem to work best are NGK SIKR 9A7. These have fine iridium wire center electrodes, platinum tipped ground electrodes, and projecting tips. They do not appear to wear or corrode from race fuel blends. The set I have will last to the end of my racing career.