67 barracuda seat belt mounting location?

Where do the lap BELTS for a 67 barracuda bucket seat mount? My car has carpet, no holes other than the 4 seat posts. I was assuming the big post in the lower seat is the mount location (that post the seat back rests against, but my new aftermarket BELT holes do not fit that). Photo anyone? Thanks!!

I’m fully rebuilding the seats this week, will take some videos if anyone is interested.