Many, many years ago, I owned a '70 Nova SS that came with a windshield antenna. I was never happy with the reception and installed a power antenna on the rear fender. All this was too long ago to swear to the amount of improvement, but I remember being much happier with the reception (or at least with the work I put into the swap ).
Back then ('71 or early '72), one of the most difficult aspects of the project was finding a power antenna with a 'base' small enough to fit on the very narrow top of the Nova's rear fender!
My car came with no radio so I have no history as to how well the windshield antenna works.
I've installed a hidden stereo that has Bluetooth. I will use that for music. It does have AM/FM capability that I thought I'd make work. I think I'll let that go.
I've never been a fan of the windshield antennas. Reception is generally fairly lackluster.
And, as an added 'bonus', if the connector 'button' ever, for whatever reason, pops off the windshield, reception goes from poor to terrible (or worse) until you replace the windshield.
I think the best option for a 3rd/4th Gen Nova is a hidden antenna. A decent one will receive FM stations well, but you will lose AM reception with most, as long as they're hidden.
On the affordable side, with relatively decent reviews, is the Dakota Digital hidden antenna.
There are also quite a few options on the market that are nice and compact but still have AM capability, because they're designed for motorcycles.