Question about ground clearance on a lowered truck

[Mathew21]

OK a little background first. This is my first car or truck I've owned that has been lowered. Previous to this I always had a Lifted Jeep or Truck.

I'm just wrapping up a front crossmember swap out of a 91 Suburban in my 66' pickup truck. I installed 2" lowering springs along with CPP 2.5" drop spindles. The rear has not been touched yet but I have a set of 4" drop springs that will be installed as soon as I finish the front swap.

I have about 4.5" of ground clearance under my lower control arms now that is lowered. Is this enough to drive around town and go up driveways? I know I'm probably just being a little paranoid but it don't seem like much clearance.