I have also thought of the torrington bearing idea. The biggest thing I hit was you can't just slip it over the crank, you would need a two piece bearing that bolts together around the crank. I don't know if they exist or not. Then I started wondering if it would be possible to add one somewhere else.
The other thing I encountered was a modification to the thrust bearing it self. It's on
this page for those of you that haven't seen it. The idea is basically adding an oil passage right to the thrust surface.