Bench to bucket seat question, 1970 Dart

Okay, my 70 Dart came factory with a bench seat. The buckets I plan to use are a factory low back bucket seat (no head rests) from a 68 barracuda. I have the seats and interior torn out, and I set the bucket seats in place.

From what I have read before, I thought the factory had put "dimples" in the floor on bench seat cars where the bucket seat would have been mounted if so equipped...Well, I do see "dimples" but none of them line up at all with the bucket seat tracks, where the 4 posts go through the floor...

Maybe I'm missing something??? How do I mount these seats in the proper location? I'll try to get pics up tonight...