I've seen the CAD for the 7 port they've been testing, which I'm assuming is the same as the 5 port, plus 2 thin exhaust ports at the top. The reason there may only be a 5 port is I'm told the powerband on the new 5 port theyre testing is extremely wide. Punchy like a GX-5, but winds out like a GX-7. Only more power than both w/ better mileage.

Easiest way to describe it is instead of "fangs" the ports are worked so that theres more efficient flow between the ports. i.e. if there's resistance going into one port, the bypass ports are going to be more effective. outside of that, I cant say anything that wont give it away. Front intake port is worked too, all of which is a change from the current and previous generations.

I will say this- Everything on these motors is new. From the ground up. The only thing that remains the same is the bore and stroke. That said, I'm told the new P/R/S will retrofit into the GX block. I obviously havent been able to do this myself, but you can bet I'll be trying it as soon as I can!