The plates sit on top of the lower flange and the crossmember bolts on top of the plates so those plates are spreading the load on the lower flange. The factory crossmember bolts to the inside of the top frame flange with only the bolt heads supporting it at the flange. The factory braces support the crossmember from underneath to the inside of the lower frame flange. Just to be clear, this is not like a regular married transfer case 4x4, the transfer case has it's own crossmember about 12" behind this one that is riveted to the frame rail sides near the top flange. The crossmember you see here only supports the trans.