If you are going to rev it and want top end power you need the port flow of the bigger heads. this isn't a battle this is the truth of 1 reason why the 340 revs to 6000 rpm and can be built to 400 HP. Another is high comression The vizard build will end up with a 4 barrel and bigger port heads wait for it. Those who beleive Uncle Tony are being played for suckers by a snake oil salesman. the initial claim was like a red lazer to guide the pussycats over to Vizard's newly built channel.