So I did some compnenet speaker swapping and head unit swapping on my truck and I was looking in the back of my Monte and was wondering if i could take the stock amp and replace it with an after market one using the same wires and mounting position? I want to put new 6x9's in the rear deck so I figured an amp would also be a good addition while I'm back there. Any information would be awesome!

 

You can't reuse the factory amp wiring with an aftermarket amp. At least, not the power and ground wires. And it'd be easier/cleaner to run your own signal and remote wires too.

You might be able to mount an aftermarket amp up there, but you'll have to make your own brackets I would imagine. IIRC the bracket that holds the factory amp to the trunk is built into its housing.

Also, if you do add an amp, don't just amp the rear speakers. The fronts are more important.