I would go with 34mm valves and an intake with at least .431 lift....you might sneak by with a .425... and a duration of around 255 @ .04 or 1mm. Use the current intake on the exhaust. The current set-up cannot keep up.....the window time/area is inadequate. I would suggest that the exhaust valve should be increased by 1mm as well. Get other opinions as well.