Bucket seat track spacers

Do you mean the metal re-enforcement pads? I dont know if its the same, but my 74 Duster had them on just the inner tracks (near the tranny tunnel) both front and rear studs. The outter ones didnt have any spacers. I think they were just a square piece of ~14 gauge metal with a couple tack welds on top of the floor.
Also, the outter ones are re-enforced under the floorboard with the peice the goes on the rocker for re-enforcement. As far as I can tell, the buckets use totaly different mounting holes than the bench seat,on mine, they left the bench seat holes open under the carpet, as they are higher up and closer to the door.

Mine is the same deal. I'm changing from bench to buckets in my 69 Dart. I have installed the metal reinforcement plates on the inner two holes on both sides on the inner holes and like yours my bench seat mounting holes are up higher and not used. But i though I heard that you also needed to use two like 1/4" seat spacers on two of the mounting studs? But I'm not sure.