If you want new parts try www.redline-ci.com. He can get anything that is still available, and the heads probably are. Fixing the cylinders is more complicated than boring them out. I'm not sure they can even be bored out since I don't think oversize pistons are available. The cylinders are Nikasil plated and that needs to be restored to OEM spec to fit new pistons. But like Charles said, lets check your stuff out before jumping the gun. I would be more worried about the crank.
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james
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