My 408 is a 5.9 Magnum based build with Hughes internals. I did end up cutting the torsion bar cross member away from the actual tunnel portion of the floor. Before I cut it, I welded a 1/4" thick 3" wide 2 foot long strip of steel on top of the floor where the cross member is. I really had to heat that metal strip up cherry red and hammer on it hard to get it to bend to the shape of the tunnel before welding. I also made sure the welds penetrated into the cross member under the floor. The torsion bar sockets likely exert significant forces through the floor hoop, and the plate I welded on stabilized the area.
