Does it make a difference on a torsion spring whether its left or right hand wound?

Yes. To reduce the likelihood of torsion springs taking a set, the spring should be coiled in the direction that results in increased coil count as load is applied. In other words, the spring should be coiled such that it “winds up” when load is applied. If the spring “unwinds” as load is applied, it should probably be coiled in the opposite direction.