Why would you want to rev it higher in park? Reving the engine under no load isn't good for it at all.
As for the governor (set at 108mph on a non-supercharged 3800), it'* there to cover GM. Base Bonnies got *-rated tires and GM didn't want people going out and getting themselves killed because they took it up to 120 and had a blowout.
The other reason is that the 4T60E isn't designed to shift from 3rd to 4th gear at those high RPMs it would be turning at 110+. Imagine taking it up to 125mph or so, then you let off. The tranny goes for 4th gear and BANG. Ouch. That'* why, on the supercharged models, which have a 126mph governor, 3rd gear is only good for 108mph, after that it goes for 4th, even though 3rd hasn't come close to redlining yet.
BTW the speed governor works by retarding the timing, not cutting off fuel. That is why, when you hit it, you can hardly tell, except the car just doesn't pull anymore.
As ppl pointed out, you can get a chip to change all this. But I just thought I'd warn ya. If you want to do triple digit speeds in a Pontiac you're best off buying a Formula or TA...JMO
1992 Pontiac Bonneville SE, 163k miles - RIP (blew the transaxle)
1995 Honda Civic EX, 5psd