One wire lock-up, 4 spd automatic w overdrive into A-body.
I would consider welding 3 inch wide, 1/8" plate under the car to cap the open torsion bar member and follow the floor contour. Then add another 1/8" 3 inch wide plate on the top of the floor to follow the one you've installed on the bottom, but be sure to line both ends of the torsion bar member back to their original positions first. If they are dropping down, maybe using some of the weight of the car to push them back up using jackstands underneath it would do the trick. If they are pointing up, you may have to disconnect your torsion bars and use a block of wood and a big hammer to get them back lined up before welding?
You could drill a few small holes along the area you want them to line up, so you could see that they are lined up. If you could cut 1/4" off the upper plate, it would make it much easier to weld the top plate through the floor to the bottom plate. Just a thought.
Using multiple layers of flat steel to strengthen a curved surface, while not ideal, does add a lot of strength to that area.
Good job on welding the entire crossmember to the floor. Add a lot of strength which you really need.
My Dart has 1" torsionbars and a 518 for which I removed the top half of the crossmember in the tunnel.
I hadn't found the time yet to install a reinforcing bar on the outside of the tunnel in the driverscompartment.
I posted this image on Moparts yesterday aswell;
Below is what happens when the crossmember is 'weakened' on top and the floorboards aren't welded to the crossmember...
After I noticed this happening on both sides of the crossmember I also decided to weld the crossmember to floor as good as possible.
I would consider welding 3 inch wide, 1/8" plate under the car to cap the open torsion bar member and follow the floor contour. Then add another 1/8" 3 inch wide plate on the top of the floor to follow the one you've installed on the bottom, but be sure to line both ends of the torsion bar member back to their original positions first. If they are dropping down, maybe using some of the weight of the car to push them back up using jackstands underneath it would do the trick. If they are pointing up, you may have to disconnect your torsion bars and use a block of wood and a big hammer to get them back lined up before welding?
You could drill a few small holes along the area you want them to line up, so you could see that they are lined up. If you could cut 1/4" off the upper plate, it would make it much easier to weld the top plate through the floor to the bottom plate. Just a thought.
Using multiple layers of flat steel to strengthen a curved surface, while not ideal, does add a lot of strength to that area.