thats why im "thinking" about it lol, i just made a subframe just like yours but with 2x4 . im thinking i may need more than that with rockwells and a v8 and a whole new boxed frame would be insanely stout and my xj body would basicly be sitting inside my cage ontop of the frame
i may use 4x4 box or 3x3 , wonder if they make 3x4
and it would make a perfect base for when i go coils all around