For the "what it is worth" dept,a while back I talked to one of the guys at Just Aircraft at an airshow up in the mountains of NC. They had a Jab 3300 installed in their Highlander for testing and had just flown in. I asked how it was working out . He said it was a good strong engine but it did have a tendency to overheat when it was warm out so they were "step climbing" it to keep the temps down. But he also mentioned that they were working on the baffling to try to control that.
You might give Troy a call at Just aircraft to see how it is working out. I think overall they are pleased with that engine.
Dick Maddux
Fox 4
912UL
Pensacola,Fl