These were custom built 16 years ago and the car they were in was on the road for only one season. There are less than 300 miles on these guys and they are in pretty good shape. Made from steel and HPC coated. The distance from the center of the port to the flange is 12 & 3/4" and is dumped in the center. Engine was a '66 401. $250 plus shipping costs. Any questions please e-mail me at: lance.sorchik@gmail.com as I am not on here all the time.