Be careful, as is you would blow your engine if you upped the rev limiter. The reason all bikes have limiters in place is to keep you from doing so. Your stock springs/valves/guides (should do them all at once) can only take so much stress.
If you want to up the limit, do some headwork first. Then if you do the headwork, you should eventually replace the cams as the stock cams really aren't designed to rev that high so in order to take advantage of the new top end you should swap them out for at least B50's. Then go ahead with the limiter. Done properly you can take it up to 8K, but you have to know exactally what you are doing, or boom!
Another thing to consider is that there is only one aftermarket adjustable ignition that will retain the AE, in other words you will have to hardwire it unless you have the SE ignition (which is hard to find, obsolete).
Don't let me discourage you,
I have 8K limiter in place with SE ignition and proper headwork.