Hi Root,
If you have .27 degrees on one side and .38 on the other side, you essentially have no caster and your truck should steer easily but wander around like crazy. If you find some 3.5 degree shims, install them in place of the 2 degree shims, you should get a bit under 2 degrees positive caster and that will help. But something has caused your caster to be out of whack. Let's see if we can help figure that out first. Are your rear tires taller than your front tires? Do you have all 8 spring leaves on front and rear? Has your rear end been lifted (or your front end lowered) for any reason?
Jon
