The lower control arms mount to a bracket that cradles the bottom of the frame. The skidplate bolts through it into the stock skidplate holes. However, whenever you need to service the transmission or T-case and drop the skid plate, the lower control arm brackets are no longer bolted in. We traced the outline of the bracket on the frame so that we could grind off the paint for a good weld. As per the instructions, this will only be stitch-welded.