I was more wondering if another exhaust for the '06-'07 GSXR 600/750 would fit the 700xx. I saw a Yoshimura RS5 Carbon Fiber used that looked like it may fit, but I don't want to waste $200 for an experiment.
I think it fitting has a lot to do with the angle of the piping going towards the muffler and how the muffler mounts to the quad. If you'll notice the two brothers has a strap that goes around the can that is adjustable. IMO this is the key to making it fit as it's able to be angled a little and it's also able to go backwards and forwards.
I know Jeff had some issues with his working loose but resolved them by making another support or something like that.