In my AM head all 3 exhaust ports looked like a middle port pictured above. Did all three according to Triumph bulletin and am happy with general performance of the bike. However in my A65 exchanged a head in fourth year of ownership from big port to small port head and the result was tremendous not only with an added torque below 3000 rpm but everywhere. Much more fun during town riding and because I live in very big town, more fun altogether. Finally that bike looked to be capable of 100 mph and I tried 90 mph for quite a distance. So yes, I'm very curious of this reversible change Stein Roger did.