Well, the good thing about using Fireball tires is that they give the dimensions.
Check the stock tire size and compare them with the listed dimensions.
Back in the day I ran L60's on the rear of my 70 Chevelle and they barely fit, and that's with banging out the inner lip, so on a Nova that might be a stretch as they are a tall tire, at least on a 1:1.
When we were rodding we never used anything but 15's. Novas, Malibus, Chevelles, we had them all and used 15's on every one.
I say mock up the chassis onto the body and measure how wide a tire you can fit in the wheel well, being sure to leave room in the front so it looks like the wheel would turn then go for it.