stock radio questions

[dishow]

hi. my truck had a aftermarket CD player in it when i got it. I wanted to return it to a stock radio. i got a dash piece that deletes the cassette and a radio and amp from multiple parts trucks. I didnt pay attention when I was pulling the amp from the parts trucks so now i cant remember where it goes. I remember its by the steering column?just cant figure out where it goes.and also, do the amp and radio have to be from the same truck? i just picked these out of the pile I had. would like to get this hooked back up so I at least have a radio to listen to. thanks.