1991 Dakota 318 TBI Belt Tensioner made of Unobtainium

My TBI motor doesn't use a tensioner - all v-belts.

Autozone lists one for the '91 that shows a smooth pulley, but it's unavailable. The specs list the same as the '92 vintage from rock auto, but the rock auto part is a grooved pulley. Sounds like maybe just a pulley swap is in order but use the magnum tensioner?