Upgrade steering

The big boys have a steering sector on both frame rails. Sounds like you just need to find and fix your problem.
First is checking for mechanical problems. Then fluid gallons per minute and pressure.
What all have you done after asking and searching?
Removing the blocks and causing excessive caster can cause that crap load of weight feeling you described earlier. You said it was aligned, do you have a read out on alignment angles and degrees?
You also had post about bad vibrations. Was the back lowered also?

 

Western Star uses a hydraulic assist cylinder on the passenger side. A lot lighter than a 2nd box.

 

You said you lowered the truck? You might be getting "bump steer" thats when the angle of the drag link is wrong and it causes the wheels to turn one way or the other when the suspension is compressed from a bump. Look it up online and see if it applies to you.

 

Can you do pics of that spring, bags, stops, and drag link set up. Don't thank the column would jolt the whee when you when you fall in a hole.
So is that the real problem or is it also hard to turn on flat ground?

 

Is your truck a t600? What year is it? Does the collumn you got pivot down by the dash or up close to the wheel? Either way it shouldn't make it hard to steer when stsnding still.