at our local dirt track we had a broken straight exhaust pipe go through the floor and into the driver through the (plastic seat) killing him . so think safety first.
You think a stock seat or even an aluminum one is going to change that? Sounds like driveshaft loops were not being used...
Op, I have them in my 68 dart and they are better fitting than the stock seats (bench and buckets) while being more comfortable, that is unless you carry lol