No owners manual ... Does this car have a3 or 4 speed transmission?

Hi, I have the same question. A friend has inherited a 1989 300 Benz. It's been driven very little over the last few years. The issue is that it I don't think it's going into the last gear. I'm seeing 34K RPM at 65MPH. Did you ever get your question answered? If you can help I'd appreciate it. Thanks, Rick - arq0088@gmail.com