Installing an aftermarket radio in an F-body is very easy. You will need a radio mount, harness adapter and antenna adapter to install your new Alpine though. With those things in hand you can install your radio in about an hour at the most. I carry these items if needed. Another consideration is your steering controls for your radio if you have them. PAC makes adapters for about $50-$60.00 that allow you touse your steering controls with your new radio as well.
My alpine just came in today. I got the Metra Adaptar harness, and the Metra 99-4000 kit it looks like the one on Kee Audio and said it will fit GM 82-04 so it will most likey work. Damn I forgot to get the antenna adapter. I'll just go after school to car toys or some shop that's near by and get it so i wont have to wait on shipping so I can install my alpine ASAP. I'll keep my post's up cuze i'll probley need help when the installation comes.