The 111 body coupes (220se, 250se, 280se) had spring suspension, the 112 body coupes (300se) had air bag suspension. The last of the 300se Coupes was made in 1968, the 3.5 V8 was introduced in 1970.
The 3.5 coupes were all 280se models and had spring suspension.
The 109 (300sel) sedan had air suspension and was made with V8 and 6 cyl. engines 2.8, 3.0, 3.5. 4.5 and 6.3