Running too high of an octane will just make it harder to start.... completely unnecessary. Especially since nothing is done to the timing or the compression to take advantage of it, and a jetting change would more than likely be necessary.
Don't do it. My buddy did it when he first got his brand new 07 last winter and it had a 4.1 pipe. We put it on the dyno at school and it ran super hot and the header was turning cherry red. Plus it ran like crap.