Ran 4.30's in an 04 gt. Not the same by no means. That car LOVED them.
My best friend has a 12.50 89 lx that runs 4.30's. Its a monster but the pushrod cars don't like 3k at 70 on the hwy. Takes him forever to get anywhere far.
If its just a toy(like my buddys) and your not worried about running out of gear then do it!
EDIT: b/c I know someone will say it as well. You can run a 28 inch tall tire (stock is 26) and get away with a taller gear but if its a GT you will have bad rubbing issues and have to roll the fenders even on an lx.
We really need to know what you plan on using the car for. street/strip. Drag only? Daily driver?
They'd be fun on the street...but a total basturd on the highway! I personally think there is a limit to gearing on a street car, and i feel its 3:73's on a 5 speed fox. Anything more and your really running the engine hard on the highway at high rpms and giving it extra wear.
I drove in a '95 Gt with them. They were to short in my opinion for a daily driver. My buddy ended up getting rid of them and going for a little bit higher gear.
For what your plans are, I say go for them as long as they match your trap speed potential, transmission gear, and tire height.
The more power you have, the less gear you will need