Sport Trac seats are 99% bolt in, all you have to do is enlarge / elongate 3 of the holes so they line up with the ranger floor holes and so the ranger bolts will fit through the rear ST seat holes. very easy to do.
Now air bag sensors and seat bealt tentioner wiring in the ranger are a interesting story..... ranger passenger seat has a pressure sensor in it, it's a liquid filled pad between the seat frame and the foam, I believe it could be removed and transfered to the ST seats with a little effort.
Drivers seat in the ranger has a seat position sensor.... haven't really looked at it too closely yet, but once again, with a little fab work, I believe it could be transfered also.
seat belt tentioners in ranger are long cylinder like things attached directly to the female buckle, I have just bolted the ranger buckles to the ST seats for now, no wiring hooked up, so as of right now, my air bags are disabled. if you get ST seats, be sure to get the seat belt track, you can just leave it attached and just use the ST female buckle with existing Ranger male buckle, they fit and latch. I made the mistake of only grabbing one, forgot the other one in the ST bed....