The 4th gen was based on the Prado 120 chassis, the 5th is based on the Prado 150, so the frame is different. That would lead me to believe that the frames are not dimensionally the same as the 4th even though there are a great many parts that are interchangeable. Skid plates, for example, don’t seem to be interchangeable from 4th to 5th, another clue that the frames are not the same.