Truck wanders on the road

[chevymotocross]

I have an 87 silverado 2wd swb. Ever since I bought the truck, I never really liked the feel of it on the road.... especially highway. The trucks balljoints, tierods, and wheel bearing are all solid, no play. What I do notice is it has alittle more resistance turning the wheel left, than right, just a slightly more drag to it but nothing drastic. The truck likes to pull to the right. I had pep boys align in 3 times and it still likes to wander to the right, they claim it could be a worn steering box. When sitting in the truck, engine off, there is about almost an inch of free play at the wheel, left to right. Also, when I brake hard, the truck really likes to pull hard to the right. I've had cars with bad calipers before, but you usually know for sure it's a bad caliper when it's literally almost stopping the wheel, the truck does not do this, I doubt it has anything to do with a caliper. When I'm on the highway, the truck likes to "wander in the wind", and not track a straight line. Kinda scary. It's not totally drastic, but enough to make driving annoying. Any suggestions?