After looking at it will napping under the truck, I decided to just cut the crossmember close to where the riveted section is, cut a piece of plate steel to weld on the end of that stub which drops down 2 inches. (I need more clearance anyway.)
I will then weld a similar plate to the end of the original crossmember which will extend upwards, parallel to the plate previously welded to the stub ends of the crossmember on the frame.
I can then drill holes through these plates for bolts to hold everything together.
Total cost of materials $0.00.
