Plate the brackets.....install the crossbar.......weld it to housing.......and also, do NOT just weld crossbar to inside bracket on both sides and call it good. Take the time to fit the bar through both plates on either side and weld it all up.

You are NOT going to keep your dana housing from bending, so do all you can to help it. Plus as mentioned, this keeps you from laying the brackets over and ending up on the rooof