A couple ideas come to mind... 1. Jog the engine to the passenger side a touch.
2. Disassemble the steering column and modify the steering shaft with a smaller solid stock. I suppose you could even make a weld-in coupler insert deal that would reduce the diameter in that area.
3. Yes spacing up motor mounts might do it too... as you said header clearances may be hurt with that though. Try it and see!
