Alignment Specs For 2004 Silverado 2500

[pvanwagner]

I had my 2004 Chevrolet Silverado 2500 aligned at Firestone and have been back twice for rechecks on the alignment. The first two times it was pulling to the right after being aligned. Now it drives like a boat with the rear end fish tailing back and forth. It feels like a big car does when the rear tires are low. My questions are:

 

Are there different alignment specs for a 2500 vs. a 2500HD?

 

Is it possible that they used the wrong specs?

 

Can you provide the specs for a 2500? I have the printout in my glovebox that they provided after the third alignment.