Gianni,
Nice work & looking forward to the finished results.
Reading through the post, I noticed Kaw Rider mentioned "freeport" & it looks as though the exhaust Sub Ports & the Front Transfers will be open @ the same time with That Piston with the sides cutout that way. Freind of mine had similiar situation because of the cutout of the piston and the bike ran nowhere near it's potential until he resolved the piston problem. Thought you would like to know now to prevent future headaches.