I agree with Wayne and Robert. I clamped the tabs as straight as possible and drilled to match the holes. This works best if the connectors aren't already welded in because I drilled in from each side, rather than all the way through. I used two crush sleeves per side assuming the end cap would stiffen the hole closest to the end. I just drilled a small hole and plug welded the sleeve to hold it in place. Here's a couple of photos. Once the tabs are tacked to the subframe then take the bolts out and the tabs stay with the frame to be welded later, or immediately as you like.
Scott
