[Daves55Sedan]

If I were going to make one, I would make it out of minimum 1/16 inch thick steel plate. The drawing above does not take into account the fact that the factory crossmember is taller on the backside, which accounts for the slant downward at the bottom for condensate runoff. I believe that slant should be duplicated and that the very bottom at lowest point should have three equally spaced 1/4" diameter holes for water drainage. The drawing does not show the top piece which is wider than the lower part of the crossmember. I would duplicate that and allow for re-installation of the engine steady-rest mounting piece which would be cut-off the old bad crossmember. Not sure what I would use for the two tubes inside the crossmember, but I would have the split facing downward and only have the pipe spot welded to the inside of the crossmember wall at the top of the pipe to allow it room for expansion when the pins are hammered in.
For painting, I would primer the whole inside and underside of the top piece BEFORE welding of the top piece to the crossmember, using weld-thru primer, and to some degree also spread some rust-o-leum black to the interior of the crossmember before welding the top to the crossmember. Next, the top piece could be welded on to the crossmember. Finally, after sandblasting the old engine steady-rest piece, it would be coated with weld-thru primer top and bottom and welded on to the crossmember assembly. Finally, tape edges to be welded and spray the finished crossmember all over with rust-o-leum black. Now ready to be installed in car frame.