Do you have the Salty compatibility mod installed as well? If not, go to Flightsim.to and just type "767" in the search bar and it should show right up. The developer has done a lot with this mod and is working on improving the flight dynamics as well. After a recent update to this mod, it has been difficult to climb past FL290 but he is working on that. To get around that, I changed the "engine static thrust" in the engine.cfg folder to 70000. I was able to climb to FL340 with no problem.