Swivel Seat Retro for Ford E350

I also put some washers between square tubing and floor. Those were needed so that the bolts and nuts that connect the bracket to the square tubing would actually clear the factory bolts that bolt the square tubing to the floor. Of the entire job, the bolt clearance was the only partially tricky part of it. I could have tried reversing the bracket to tubing bolts so the nuts were on top. That would have given plenty of clearance without the washers, but I had a hard time getting the bolts to fit that way due to the length that I made the square tubing. It was easier with the bolts facing downward...but it required the spacers between the floor and the tubing to make proper clearance. For safety I used grade 8 bolts.