Not like most TD trailers but I built like I know. And I know how we use to mount truck beds on farm trucks. the new iron the springs are mounted to are 3x3 I forget what thickness, will have to messure if someone realy wants to know. But it will work. Front one was clear across but I cut the center out so I can have a foot well. I didn't want to cut the old iron apart and make it wider cause that stuff gets real warpy when you do that. I later put the axle on top of the srings.