Suspension

2.3L Mustangs have a different steering rack than 5.0 Mustangs. Their rack is 3 turns of the wheel lock to lock while 5.0's have 2.5 turns lock to lock. The difference is pretty significant as i have a 2.3L rack on my car and hate it because, as you said, the steering is way too loose.

5.0 springs are not that great anyway. You car would be 10 feet off the ground and would sway like crazy when trying to turn. Aftermarket springs and shocks are the way to go.

Could also upgrade to a 5.0L front sway bar and add a 5.0L rear swaybar