So here is an over view of how my rack goes. The rail is a 6-foot pieced of aluminum that is about a quarter inch thick. This is C channel. I have a piece of plate steel that is welded to a 2-inch piece of box steel. I then bolted the c channel to and threw the plate steel along with the 2
inch box steel. I then took some angle iron to make extensions for my tie downs. Threw some eyebolts on the ends of the angle iron and its done. Its easy to do and takes no time.
The 2-inch box steel is a quarter inch thick and 29 inches long. This varys on the type of truck you are using.
I dont like it to be to long as it creates more leverage hanging off the back.