Ok heres the rails and tranny plate from the bottom all done and welded in.
Ok here you can see inside the tunnel. You can see the bushing sticking up from the plate this supports the tranny input all the way up to the case bottom. Also if you can enlarge the pic you will see how the rear plate is welded in not just bolted but all done on the inside.
Ok here you can see the support I build that fits inside the dash. I use the same tubing as I did on the frame 3/4 thin wal. It has a place for the shaft to go thru and placement of the upper column and bearing support.
here you can see how it fits snugly inside the dash. This dash support has taken a 60 mph end over end kart wheel with out busting the plastic dash
Ok on to the steering column and its bearing setup. Here is another product E.C sells, its a universal weld in bearing mount and 5/8 spherical bearing. These work well on uneven and even surfaces where you mount on metal to weld them in I use one top and bottom.