Pardon my ignorance, or just plainly missing something here, but... what is the purpose of putting in larger valves in a head,(other than having new valves) if nothing is done leading up to that valve? I just don't see any gain at all in doing so.
Ask the machinist that did these, it was his responsibility to properly throat and top cut these.If you just put in a large valve and do nothing besides cut a massive 45... it will flow less air.
These heads 'as delivered' were not suited to be on any engine. The valves sunk so bad nothing could hardly get in or out at .100-.200
