If anything, the caster should have the right wheel base slightly shorter...

ok so the passenger side wheel base being shorter by a 1/4" is okay then?

so reading that was hepfull, i understand it a little better now, so could the power steering pump have something to do with it pulling to the right or am i just reading that wrong...probably a dumb question but i am grasping at straws here lol

so any body want to buy a truck lol

That is what I was doing too, grasping at straws. If it is power steering related, the problem will stop once you shut the truck off.

i cant think of anything the ps pump would do to cause a pull to one side. did you replace the tie rods, idler/ pitman? what about the rear if it was off it can pull too, and alot of times the alignment shops over look the rear on trucks and things like that

yes tie rods ,idler , pitman, the whole front end was done. I got an appointment at an alignment shop in another town a few miles away, talked with him and told him everything , he figures its the tires causuing the pull he said the 1/4" difference IN wheel base can be adjusted at the front and that the 1/4" diffence wouldn't make a difference on a half ton
so I will take it to him and see what happens, I will keep you posted

ok so i git the wheel alignment done at this new shop. this guy was great. Randy'* auto in International Falls MN. made adjustments and took me for test rides. got it set up so the pull is hardly noticeable but still can tell its there. he did a great job. it is way better. he thinks it has to do with my steering box said he has seen it before where the box sends more pressure to one side so you get a constant pull to one side. he has had it happen on a few other Chevys. about 400 for parts and install not a bad price. he checked every thing else even rear end and it is all good. everything lines up. for now i can live with it ad it is way better but may change the steering box in the future and will let you guys know if that completely cures it. guess you just gotta find the right shop to go to eh.
anyways thanks for all the help and input on the issue. it is greatly appreciated.

Thanks for letting us know how the new shop did with the alignment, hopefully it stays like it is, if not at least you have a good idea of what needs to be done to fix the issue.

edit: Didn't realize this thread was three pages and was about to respond to page 1 with this exact suggestion. When steering boxes, or steering shaft U joints or rag joints get old and worn it can cause a "ghost pull" like you were describing. It'* there, then it'* not, then you take a turn and it'* back again. In some worse cases, I've even seen the pull shift from left to right, then back again.