Oh, one other thing. "Road crown" can cause a vehicle to pull while driving. Often people will try to compensate for this by adding positive caster to the left front wheel but please don't let anyone try to tell you that will help on your truck. They can add caster shims but all it will do is to cause the spring on that side to flex more when the spring to axle nuts are tightened. The axle is about as rigid as a railroad track and causing one side of it to bend by adding shims is folly.
