It was the state Sports Sedan associations that reformed the class from "Sports Racing (Closed) into Sport Sedans and not really CAMS.
The highly modified cars could have kept racing as Sports Cars.

I just love the freedom of sports sedans. Your open to express whatever ideas you want to put into a car, without the myriad of rules and bullship interpretations that follow. Love the honesty

The engine was originally a 5 port Mk1 S engine in race spec. John was good friends with Richard Longman and acquired a head and split webers on manifold off Richard own race car, whilst he was in the UK. John also had a supercharger setup for the car, which I sold on here to I believe was Monaco (from memory). Was a really nice kit and great for a road car, but not an ideal setup for a race car. Appart from that, yes the lack of weight and aero advantage had something to do with the car's performance. John was quite well off compared to most racers, and always managed to have the best money could buy, so looking through the engine and spares that came with it, theres no wonder it was competitive.

I seem to recall an advertisement that used to appear regularly during the sixties in Modern Motor and Wheels magazines for Ekins supercharger conversion kits for Austin 1800 B series engines too. It was claimed to transform the car's performance.