LIMEGREEN71

I'm about to begin a bucket seat conversion on my '71 Supreme Convertible. I've done extensive research on the procedure and did purchase the reproduction bucket seat bracket kit (repro. of the original rather than the conversion kit). I need some experience and wisdom with the correct way to fasten the outboard seat track rear bolt to the floor of the car (doorsill side). The reproduction kit comes with the trans tunnel bracket, which includes the studs for fastening the inboard seat track. Also included is a stud for the front outboard seat track bolt. Do you use the existing bench seat hole for the outboard rear bolt (hole in floor with nut welded to bottom of car)? If so, my assembly manual still shows a nut used on the topside, just like the other positions are fastened. So, does a bolt come up from the underside of the car so that you have another stud or is correct to run a bolt from the topside, like was used on the original bench seat? Any experience and answers would be a great help. Thanks!