I'm assuming it's the 2.8 v6. If you to keep things simple you could swap a 3.4 from a later Camero in its place. I'm not super familiar with the 3rd gens but if you're carbed you could just swap the intake from your 2.8 onto the 3.4 and it will give you a slight bump in power.
You could always go the LS swap route too. Thousands of parts out there to make that happen