Jake Brake?
 

I am busy putting my beloved old 74 240 D Pearl back on the road. It's main use will be to use on the rough forest service roads and to use to go to fires and patrol for neighborhood watch, It will take a load and beating off my regular driving cars and as I carry a lot of equipment for both duties I will be able to keep it all in the trunk and not have to do constant loading and unloading...
Now the question1 since I live in the Coastal mountains here in Oregon I thought it would be a good joke on the log truck drivers to make a Jake brake for my old girl, has any one ever heard of doing this on an MB diesel? any ideas? P.S. meant to post this on Diesel section sorry.....
William Rogers.........

http://www.dieselperformance.com/

They have some jake brakes. That would be pretty funny, but why dont you just turn on the A/C, that should slow you down.