I just had an Optima red top type 34 installed in my 87 300E, 960 Cold Cranking Amps. Call the Toll Free number: 888-8OPTIMA (888-867-8462) and work your way through the menu until you talk to a real person (They have a battery selector on the web site, but it comes back with 'none available' for any of the MB models I tried.)
The helpful person asked about the type of load (if I had a competition stereo, aux driving lights, etc) and determined the right one for me. They make deep cycle and marine batteries, and list MB trucks and farm tractors, so I bet they have something for yours. The type 34 was smaller than the factory battery tray, but fit well and secure in the tray.
2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)
Click to see 87 300E