1995 Mercury Mystique need instructions.

Front and rear springs are never interchangeable. The front ones have to hold up a lot more weight due to the drive train, and still more during braking. The front ones are even different depending on whether or not the car has air conditioning because that adds weight too.

You didn't say if you're working on the front or rear control arms and bearings. Your best bet is to get a copy of the manufacturer's service manual and read through the service procedures. One rule all professionals follow that get do-it-yourselfers into trouble is you must have the car sitting at normal ride height on the tires before you tighten the control arm bolts. If you tighten the bolts with the suspension hanging down, the bushings will be clamped in a permanent twist that will greatly shorten their life and can cause less-than-ideal handling.