[strictlypersonl]

If I remember correctly, the Arntz is basically the same as Contemporary. The differential is mounted to a cross-tube at the top. The lower control arms pivots go through a crossmember at the front and float at the back. Contemporary uses a tie-bar at the rear for reinforcement. Trailing arms are "geometrically" impossible because of the binding involved, although some people do it anyway. I would reinforce the lower radius arms like ERA.