What is needed for the Speedy and America ignitions is not so much a higher rev limiter, but a more powerful spark at all rpms.
A company that makes h.p. ignition boxes, such as Autotronics/MSD, should be able to do this easily. I fear, though, that the market is not nearly large enough to warrant building a product at a reasonable end-user cost.
A fellow could try his own custom ign. by using two independent boxes and triggering systems. The tricky part here is installing a second pick-up coil to trigger the second cylinder's box. (I would use two independent coils, too.)
The only problem, besides cost, is: what all does the stock ign. box control, and can some of these controls be left out of a custom system? On a race bike, there would be no problem, but a street bike would be a "horse of a different color".
p.s. Great post, SalMaglie!
