Hi Matthias: thanks for your reply.

I am not sure if the cowling are only available on the 200 ver. I see here they are on the Super 27, and here is a screenshot of my 727-100 after landing, Iam holding the F2 key:

Berlopez

https://www.dropbox.com/s/p3fygq8wjm890vc/Screenshot%202014-01-18%2015.18.22.png?dl=0

https://youtu.be/ZNHoLc8gXrs

After doing some research apparently the engines that had this type of reversers were fitted onto the 200 series, they were: The JT8D-217 engines.