After an extensive search... Pac BVrake Jacobson (Jake Brake) and a number of others, Navistar said there is no such thing (They do not have it so it doesn't exist I guess) I did find one in PA. Reasonable Price
Here is the info.
http://ecddiesel.com/products/exhaust-b ... 6-0l.html#
After I get it in, I'll let you know how it is. After a week of mountians, I know we are due.