H-D Coil Springs on a 1/2 ton with 350

[77Shortbox]

Hey guys, I recently found a set of Moog HD coil springs for my 77 GMC C15 on Rock Auto for $6. Yes that's right $6. It cost $7 to ship them. So, I'm into this for $13 and my time.

I changed out both springs and the lower ball joints $60 (both) while I had it apart. And afterward the drivers side is setting 1" higher than the passengers side. I've checked the proper setting of the springs, and tightness of the ball joints and control arms. I did see that the caster is off by an 1" with the drivers side being low and the passengers side being high.
Could caster cause this?
Can I adjust the upper control arm down or up on one side?

[zieg85]

The upper control arm shouldn't have anything to do with overall height.  May have been a mix matched pair of springs and that is why they were that price...

[Captkaos]

There is variances in all springs.  You will never buy a set and the measurement be exact.  In fact over time they will settle down.  The spring itself along with the spindle location determines height.

[77Shortbox]

I'm going to tear into it tonight. I'm going to set the ride height and alignment.