early a body torsion bar ?

Yes, you can install them wrong. First, make sure they're on the correct side. After that, it's a matter of getting them clocked right so you can achieve the correct tension on them.
My bars from my unmolested 71 duster are marked <892R/221> and the other end is <UHL/892R and the other bar is marked <892R/231> and the other end is <UJB/892R>. They both appear to be right side bars. Any thoughts??????