[dsraven]

wow, that is some kinda steering shaft linkage you have going there. how much outta whack is a straight run from the column to the rack input? have you tried a broom handle or something like that to see if you can get away without all those joints? more joints = more trouble. rotate the rack possibly? different headers possibly?
can you remove the headers and mock up a steering shaft that works then see what kinda headers you could use instead of those ones possibly?
the center shaft need to have support at each end to keep the other shafts from allowing it to move like that.
what is the rack from? possibly a different option there for angle of the input?
like said previously, a shorter column would bring the rear upward and possibly allow the shaft some more room around the headers. you could easily try mocking it up by removing the shaft from the column and moving it up some at the rear, inline with the column.
I think what you have is going to be prone to flopping/binding as things wear a bit. could spell catastrophe at highway speeds.