Engine Rebuild

My engine is finally going back together after a careful examination and measure of all components. One of the cam lobes was marked and had a slight ridge, the others checked out and so did everything else so it is probable this caused the problem. It makes sense too relative to the frequency of the noise which was more like at half engine speed thus making it likely it was top end rather than bottom. As mentioned previously I have decided to go with high compression pistons as recommended by a couple of people - I'm looking forward to trying them out!