May be better keep the blocks and therefore the balanced height of the car (if these blocks can even improve something in the respect of touching the transmission tunnel at all) but swap the sagging springs against 4 leaf 4 seater springs. I‘m happy with this solution. Drive shaft is never touching the transmission tunnel any more as it was with the original springs the case.
4/4, 4 seater springs with lowering blocks retained were the answer for me - no more sag or hitting the undercarriage. My original springs were so bad the tool tray got smashed and that was when the car was new.
