Is my frame modified?

[BigSix]

Let me start by saying that the reason you see grinding, cutting, and random welds is because I have been cutting out lots of stuff the previous owner welded on for a towing contraption. And the remaining crossmember you see going from frame rail to rail is about all thats left from him that I still need to cut out.

Now the question I have is whether the frame was shortened? Once I cut out that crossmember will my rear bumper brackets have the correct holes to bolt to or will I have to weld c-channel and lengthen the frame back some and drill holes in what I welded?