[Jac Mac]

The Flange with 4 bolts that attachs to the output shaft of the transaxle should have some slight reliefs machined/cast into it to allow the u-joint to clear at this point- Have you checked to see if left & right Flanges are identical in this area.
Are both halfshafts the same length and are the inner/outer u-joints aligned?
Are both rear coilovers the same extended length- perhaps this would allow one side to 'droop further.
Jac Mac