Sounds pretty low. My stands free as you can see at 200mm what is 7.9". And is out of an original 67.I believe at one time eons ago, I measured a coupe spring on the floor upside down - spring eyes on the floor, and it was 6 1/2 inches?
I found info on Eaton Springs website. It supposed to be 6 1/4" free height from the centerline of the eyelets.Take them to a spring shop. They would know and could re-arch if not too fatigued.
There are still spring shops aren't there?