I am STILL confused as to why almost everyone here has to try to be the one to come up with the out and out racer. This is intended for a fun way for people to thrash around a circuit at speeds above what they can legally do on the road. At the last Roycroft Harry had his Light 15 thrashing around and at the end of the day put the muffler back on, through the picnic basket on the back seat and went home with a huge grin.
That is the spirit of the thing IMHO.
You DO NOT HAVE TO BUILD A RACING CAR. If I had the money and not so many other projects on the go I would buy something like an A35 go and use it then modify as I went along.