thanks for the replies guys i will get a 9x6 and see, if not i haven't got access to a lathe but i work in the auto industry so might be able to find something like that nut that i can get to fit. The engine was given to me by an old neighbor about 10 years ago, he was running it in a stock car, so that might be why he cut it down? The engine has great compression so i am interested to see how it runs.