[skidlids]

Good point uncledunnie, if I was fitting a big bore kit I would certainly like to get the Squish sorted to suit and reduce the risc of detination.

Not sure I would want to go through the hassle of bigger valves but better shaped one piece stainless valves would help both gasflow and reliability and then a camshaft reprofile with different lift and/or duration would again help gasflow.

Still that would be a silly amount of money to spend to try and beat some 620s, be better off trying to beat all the other 583cc bikes out there for a lot less cost.

Then if racing is for you move to a SoT class the following year, for about £3500 I could put a 748R on the track (my 748SP + 748R engine package that Nelly had for sale and sell 748SP engine and injection on)