i am extremely familiar with lift axles and this is not a design I have seen in the last 30 years. I am not sure what you want to do to proceed in terms of making the design right, replacing the parts that are affected or blow $3800 US on a new suspension + labour. If your budget conscious, you can go to a steel mill and ask for a 1/2"section of AR 400 [145,000 psi yield] which will s set you back $75 USD and a machine shop will precisely duplicate the holes for a few hundred more, I suspect, perhaps less. there are plenty of places that have used lift units for $500 or so, and even a grand is not too shabby.... Sometimes starting over is the way to fly, but be aware that many Mack dealers bill a half hour to drill each hole, so count your bolt holes you need drilled while in the shopping process.. If you have any question, just ask. I'm here to help. good luck there driver. edit: after further review of the photos, the cross member resembles one that was from a peterbilt [but holes are different in pic] and the upright flanges are not likely machine made as these form the gusset and there are no flanges or box shaped webbing to connect the two. .... Hartley in Indiana might be a good try, if you wanna try the used replacement route...also, I suggest you consider making the two 2"box sections a single piece 48"x12"x1/2" flat section and install new mounting studs for length if needed. you can get these at Fastenal and they will custom make them if needed. -- I also recommend you extend the cross member flange the two box sections rest on and try beefing up the hinge with a poly urethane bushing, say from Euclid truck parts and fab a new hinge bracket from that AR 400 I mentioned if you can spare the change. Most of these steps can be done incrementally to lesson the blow to your time and budget... you can also try metal supermarkets for the sections.