Thats very interesting about the vibration now being less since the compression ratio has been raised
I had been thinking back to the days when I used to play around with my old Tritons, both of them had Triumph 650 pre-unit engines, the trick then was to fit the inlet Bonneville camshaft and the higher compression pistons into the pre-Bonny engines They did go better but did vibrate quite abit more I found Chris.