Bucket seat tracks

I have a 73 duster that was an original bench seat car that I am putting buckets in. I had a set of seat tracks laying around that came out of a duster and look just all the pics I see, however, when I tried to bolt them in, the inside track is like a few inches off the floor and the outside track sits nice and tight. Is there something I'm missing, could I have the wrong year seat tracks? My 70 duster seat tracks look close to the same. Was there a difference in the floor by any chance?