I agree with Hammertime on not using the C14 or C14+. But I would use Q16 instead of C16. My dyno guy gained 20 hp on his 540 by changing from C16 to Q16. He had to jet 3 or 4 sizes. I also know of a lot of people switching over to the Q16. I don't know any prices on it, but I believe it is a little expensive though.