There's enough room to rock the rocker arm cover off? Removal procedures state to remove upper manifold first.
Picture of Camaro 3.4 Engine

 

I think Chappie is thinking of the 3.8, which you dont have to remove the manifold for. The 3.4 it looks like it does tho.

 

You do have to take the manifold off for valve cover gaskets, so I figured i just didn't have a good seal so I took the intake manifold back off and replaced the gasket again...i started it up and now it isn't smoking but its still revving too high at 2000 now. before I'd start it and it'd be at 3000 the whole time. Now when it starts it's at 3000 and it slowly goes to 2000 and stays there.

 

You've got a vacuum leak in your intake manifold. It's either the manifold gasket or it's one of the injector o-rings. Both of these will allow air to come straight into the engine. The engine then reacts to the extra volume of air in the chamber just as if you had the accelerator cracked open a bit. The only solution is to find the leak and get rid of it. One way of doing it is to take "hot start" spray and CAREFULLY spray around the intake manifold to find the general vicinity of the leak. Using very short bursts of spray you'll find your leak when the rpm increases a bit after you spray. This will help you find the leak but yeah unfortunately you're looking at pulling the thing apart again and sealing it. Realize also that gaskets aren't really fond of being tightened on and then taken apart again. This alone could be the source of your new leak. You may wind up just getting a new set of gaskets and trying to reseal again. Isn't it a treat to take that mainfold off and on with that engine all crammed under the cowl like that? The engineer that thought that was a good idea...[:@]. I hope the new one coming out next year is easier to work on. That rammed under the in cowl crap was just B.S.

Good Luck!!

Tom