The biggest problem with fenderwells is that the tire hits the headers. Keep in mind, adding caster moves the wheel back in the car, regardless of control arms. Adding tubular uppers allows more adjustment to move the wheel back further, adding additional caster. If your front tires are big enough to hit the headers with good caster, adding the uppers wont solve anything.
Now if you have room to the headers, and you need more adjustment to get more caster, then the uppers will help you.
I tell people to avoid fenderwells like the plague, because they're such a big limit to front tire size. But it's something you have to decide - if a smaller front tire is fine for you, then it's not really that big of a deal...