IMO you will be fine. Mine had the same gap before I re-tensioned the springs to raise the car a little. I couldn't get my fingers from about the knuckles forward past the middle of the top of the tyre. I have Edelbrock IAS Performer shocks that are a great shock, super stiff yet very comfy so this may have something to do with the limited rear travel play which would definitely help your concerns. Saggy shocks = more travel = more chance of rubbing and bottoming out. I have 15x8" with a 4-1/2" BS in the rear, same tyres and 15x7" with a 4-1/4" BS up front and never any rubbing issues. Having said that, not all cars are the same, someone else's JS23U car may not be the same width in the wheel housing as my JS23U car, they can and do vary.