don4331
Senior Airman
Spielberger quotes it as 14cm in his book on Panther and Variants for the height addition due to torsion bars.I don't think the torsion bars would require a full foot. Just eyeballing your picture, maybe 10-15cm?
As for alternative suspensions, what about hydropneumatic? I'm not aware of any applications to tanks in the WWII time-frame, but AFAIU oleo struts were used in aircraft so at least the principle was well understood.
Torsion bars had the advantage of being protected from mud and other debris by being inside the hull. They also allowed the Panther to travel cross country at almost 45 km/h, while leaf suspension limited the Pz. IV to barely 20km/h.
For reference: The T34 made about 25km/h and Sherman just under 40km/h
Test were done at Betonwellenband test track in Germany