Steering Wheel not centered

Hi all

I have a 1995 Chevy S10 Blazer 4.3 engine 4wd. I've had front end work. New upper/lower Ball joints, Pitman/idler arm and wheel alignment. I had the alignment done 3 times already. The truck pulls to the left. And the steering wheel is not centered. The last alignment the tech had me center the wheel. but it's still doing the same thing. The tech said it could be the steering box. It causes a head ache when driving. Just wondering if it could be anything else. I'm going to take it to someone else. But just wanted to know if there was something else I could look for. I would say I'm an intermediate mechanic. Also is it worth it. The truck has 186k miles, still the orignial engine and tranny. doesn't burn anything yet. But the tranny is starting to slip. Thanks in advance.

it is the alignment. more than likely your caster or camber. the tech should set the caster and camber first and then set the toe. the problem is the tech is paid flat rate and is not taking the time to get it dead on ask for a print out of before and after the alignment and compare that to the factory specs