well three things come to mind:
1) 2500s have the front ends wider than the rears. Looking forward from one side of the truck makes it look like its driving crooked.
2) your frame is actually crooked
3) take the truck go a good 4wd alignment shop that deals with lift kits. Once the brackets are on, no matter what the lift says, its going to change the alignment specs. So some normally great shops can't align it because of the kit(even though they say "oh yeah, we can align it" or "itswithin specs").
1) 2500s have the front ends wider than the rears. Looking forward from one side of the truck makes it look like its driving crooked.
2) your frame is actually crooked
3) take the truck go a good 4wd alignment shop that deals with lift kits. Once the brackets are on, no matter what the lift says, its going to change the alignment specs. So some normally great shops can't align it because of the kit(even though they say "oh yeah, we can align it" or "itswithin specs").