Go to Concours Owners Group Forum and lurk around and you will find good first hand information.
I ride with COG a lot, and am a member. Quite a few of them have grafted ZX14 pipes onto C14s. I have stood right beside of them in parking lots and talked to the owners. There is even one who grafted the top end of a ZX14 to the C14 bottom end, thus keeping the shaft drive but getting a lot more horsepower.
If you cannot find it, create a guest account on the forum and ask in one of the C14 topics. The site hosts C10 and C14 topic sections, plus "others", plus safety, for-sale (emporium), and a few other topics.
Living the Gypsy Life