bearings

If you reved it to high you could have moved one, or spun one or even stacked one stacking one would have loud sounds comming from your engine.

It's not good, the best thing to do is have sombody that rebuilds engines look at it, if it is a bearing you may be able to save it with out much cost. (New bearings)

I'm sorry this is not better news, Pontiacs are very good engines, however they do not and can not be reved to high unless you have some money in the engine as far as parts go. This is the reason so many people goto the "Dark Side" also known as Chevy.....

I hate to say it's a crank bearing and have it be a cam bearing or rod, you must have it checked before it shows you its parts without opening the engine up.

It's a shame it got over reved, If Pontiac was not given such a tight gap for HP engine stuff by GM because Chevy don't like it's cars beat up, things would have been better and you may have not had a problem.

If it is a rod bearing problem try to figure out who reringed what piston, if the rod bearing went on the same rod and piston you will have someone to be upset to.

Good luck I hope this helped