Need Help w/ Intake Details for '67 920 Heads on '66 273

krazykuda said

By the way, the combustion chambers on mine are at 63 cc after a clean up mill to make them true, not 57 cc like the books say....

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Was that after valve work? The valves on my last set were seriously recessed (unleaded syndrome) and needed new seats. But I imagine that changed the volume a bit.