Sorry, you can
not get new stock replacements for a Fox
GT spring. The only replacements are for the 6cyl and 4 cyl stangs. The springs fit, but they are a lower rate, not progressive, and taller.
Now, the good news,
AUTOMOTIVE SPRINGS DO NOT WEAR OUT!! The springs may break, but their rate and how much they "lift a car" DOES NOT CHANGE - PERIOD! As for all of the nay-sayers, WHAT DEGREE DO YOU HAVE? HOW MANY SPRING MANUFACTURES HAVE YOU WORKED WITH? HOW MANY CUSTOM SPRINGS HAVE YOU SPECIFIED?
For Stangs, the
isolators compress. THAT is the reason why Stangs drop over the years. Take your 20+ year old spring, put in a new isolator, and gee, the car sits at the same height as it did when it came from the factory. I'd hope that anyone that took a Mechanical Engineering course would say - well, of course, DUH!
So, the good news is that you can get any non-modified (cut) stock GT Fox GT spring, and it'll be as good as a brand new spring would be from Ford. Of course, I suggest that you replace the isolators at the same time.
The problem is finding a
100% stock GT spring. I KNOW! Seems like many are cut, or if you get springs from the junk yard, who knows what spring is really in that car! Again, I KNOW!
If you count the coils and measure the height, you should be okay. The
unsprung height WILL vary by ~1/4", but that will make NO DIFFERENCE in the final height of the car. Again, just about ALL of the BS you read on the net is that BS. It's either a very simple explanation, or just plain WRONG! Again, I'd hope that anyone that took a Mechanical Engineering course would say - well, of course, DUH!
I posted on the corral the number of coils and the height of stock springs. I forget the exact posts.