Any need to change coil springs?

What do you mean smoother, was it bouncing ? Was it a harsh ride? You can buy stock height but a better spring rate for better handling. What kind of shocks did you have? Need to know the problem for a solution. I just installed UMI stock height rear springs in my '65 for a lower look but better handling, fronts are 1" lowering UMI performance springs, KYB gas adjust shocks .

If your car has the original springs, you need new ones, if you wish to maintain the proper geometry and intended ride quality. Yes, it'll likely raise it a bit, but shouldnt be too much. However, there are MANY manufacturers and options, so if your car had no AC and a straight six from the factory, and you put big block Chevelle A/C spring in it, then yes, you'll raise it a few inches.

Get the springs that you want, not what your car came with!

Bilstein shocks will give you the best ride available. Yes they cost more, yes it's worth it.