Radial Pull: Why does my truck pull so hard to the right??

[TIMSPEED]

After I got my 3" drop spindles installed, they re-aligned my truck, and said that is has a mean pull to the right, and I should get new tires, that they're bad, and they're causing a thing called "Radial Pull". Now, these tires are BRAND NEW, I JUST had them mounted the day before the spindles went on. I drove over there and they were fine, but when I left, it was pulling like a mofo to the right. What do you guys think? Should I just take the truck to another shop and have them align it and see if they can fix it, or what??
P.S.- I have my alignment specs, if anyone knows that sort of stuff...Should be same as factory though right? Since I did a spindle drop, the suspension keeps the same geometry. (Except I put on 1" smaller diameter wheels, I went from a 29" to a 28")