There's a 4-wheel thrust alignment and then the more common simple front end alignment.
"Front end alignment" is old school. Back in the day, you could hook up either 2 alignment sensors or 4. 2 on the front only was faster and easier, but it only could only tell you front camber, caster and total toe. You don't know the rear camber or toe and the relationship of all 4 wheels.
Most modern aligners have 4 wheel sensors and measure the "total alignment". Even on a truck with solid rear axle with no rear adjustments, it is important to know the "Thrust angle" of the rear, the way the rear axle is pointed. In theory it is dead straight ahead, but that is not always the case. It could be off from an accident, rough driving, manufacturing tolerances, etc.
So you know you want a total 4 wheel alignment. Now you need a shop where the tech bothers to connect all 4 wheel sensors and use the total alignment procedure in the software. Make sure you get a printout showing all the specs are in tolerance.
A Hunter Engineering aligner is the machine you should ask for.
www.hunter.com