will the parts fit?

Doubtful. G6 electronics are completely different than the GA.

I was curious on the idea of using a G6's alternator because I thought the extra 20 amps would help cover any additional requirements in upgrading my stereo (to a Pioneer flip-out screen kind) from my GA's default 105 amps. Someone had a G6 alternator lying around to which I asked about, because my 05 Grand Am's alternator is on the fritz showing the classic 'dimming' symptoms on all my car's lights. I did scavenge another one from a 03 or 04 Grand Am which passed the tests at an O'Reilly's. Comparing them side by side, they do look deceptively similar (the bolt arrangements, the 13mm plug and the similar 'oval' clamp plug there as well on the voltage regulator side). However the G6's plug has 2 pins [in the middle] as opposed to 4 pins. The G6 alternator also has those two other plug-looking holes that look like they accept connections (I drive an 05 GA but not a G6). I wonder what voltage the pins in the oval connectors take. I tried googling but couldn't find any wiring specs for these alternator models. So I wonder what the voltage pinouts are coming out of my GA's alternator harnesses compared to the G6's voltages on its harness as well. (Left is the G6 & the right is the 03-04 GA alternator)

i have a remy 21144 alternator..will it work with my 2002 grand am