FWIW & IMHO:
The best response that I could give you is to "second' what "Spdcer34" advised. Oh, btw, I have a '87 Turbo Regal solid roof, 12K mile car, and it has the original AM radio with power antenna in it, with the power antenna temporarily broken, and it SUCKS. Period. With a am-fm, if the antenna breaks, and btw, it definitely will break, with the antenna in the down position, you can probably pick up quite a bit of FM music and stations, but with an AM only, if the antenna breaks, you pick up squat.
I am going to have the antenna fixed, and have a good Pioneer AM-FM-CD put in.