It’s because of the duration difference in the two, yes porting the head achieves air flow and as long as you’re just considering the head.... but when you add more duration that NKA allows just increases the air flow as well, so you’ve achieved the same goal but two different waysI just don't see how the ported head allowed in AKRA cannot be leaps and bounds better than non-porting in NKA. You mean to tell me you can put one engine against the other and not see a significant difference in power with the ported AKRA head?
Not porting adds the big variable.For the most part given the engine size and operating range of the engine the ports as is are probably already a touch big. Same deal with the flatheads. Valve job and correct cam and cam timing would net you the same end result given the pieces allowed. For simplicities sake for the techs and builders NKA with the untouched port removes a variable already making life simpler. I’d vote NKA.