I have seen 9063 on a up shift 2nd to 3rd...Not an over rev

 

With a blower you will certainly benefit from higher RPMs.. people with high HP from blowers see peak past 9k.. in the area of 9.3-9.4k rpms.

In stock form you can certainly rev a bit past 9k without the fear of damage, but I wouldn't go too high without upgrading various parts in the head.

 

J's N1 ECU sets redline to 9200 rpm - so, that we know is probably a decent move with bolt-ons. Not sure how much power it gives, though!