Hi Steven,
Another option if you're ok with making your own mounting brackets is Rock Auto. They have one for about $11.50:
http://tinyurl.com/q3u2z2g

If your steering components and springs are ok, you might check your caster angle. This topic has been rattled around a lot here, but a couple of points that sometimes get overlooked:
If your front tires are smaller diameter than your rear tires this will subtract from your caster angle and this will cause your truck to wander. If your springs are worn to the point they've allowed your front end to sag, this can change your caster. Also your toe-in/toe-out. Check this as a slight bit of toe-in is good and will help you not wander so much. Also, count the number of leaves in your front springs...there should be 8 of them. And check to see if your caster shim is still there. Sometimes people will remove those not knowing what they are.
Jon

~ Jon
1952 1/2 ton with 1959 235 | T5 with 3.07 rear end