not 100% sure as i've not needed to change them yet lol, with me being into rallying i managed to get these tyres cheap whereas brand new they should of cost £70 EACH!
That's the same width and a rolling radius of 1.2% less than the GT's 185/55 R14 so they will work just fine (won't foul).
The one thing I must check though is what wheels you are running. I think the stock 13" steel rim is a 5.5" width, which will be just fine. For your tyre size, you want the wheel width to be between 5" and 6.5" but do check the tyre manufacturer specifications first. It is advised that you run the same size on the rear wheels too (this may even be a legal requirement). And your insurance company will need to be told if you are running anything but the Fiat recommended sizes.