TG, here is an idea what races in our P3 Lightweight bump up class. early TZ250's CBX550's, KZ & GPZ550's, Pantah's and TT2's for example. Rain tires, radials, and even slicks are now allowed in the class, but as a P2 bike we're on our Avons.
THREE CLASSES OF PERIOD THREE SUPERBIKE:
Lightweight:
250cc two stroke water-cooled
400cc two stroke air-cooled
550cc four cylinder, four stroke
650cc two cylinder, four stroke
unlimited single cylinder, four stroke