I believe I have the 15 mm intake. I have the engine on the bike, then bought a parts engine. I did all the machine work to the cylinder I pulled off the parts engine so I wouldn't screw anything up too bad. The intake on the orriginal has a much wider opening and exits to the side of the engine, where the parts bike has a manifold on it with a much smaller diamiter opening, and it exits to the front of the bike. The inside diamiter is different on the two of them, but the outside is the same, and the carb fits nicely on both.
I don't think I changed how the piston clears the ports becasue I took all the extra material off the top of the cylinder, so the piston never reaches the area i modified.
I'll open both ports up, see how it works, then maybe move those ports down and up respectively. Thanks!