GM Performance Parts makes a Hot Cam for the 2.8L & 3.1L V6
You could mill the heads/ Cam it/ Chip it/ exhaust and youd be around 210BHP and enough torque to make it a little more fun to drive. Dunno if you'll need a higher stall converter for the auto with that cam. (Mine was a 5sp Berreta)
Check out
http://www.SDPC2000.com
http://www.gmpartsdepot.com/performance_parts.html
Threaded Mode