I ran my converted Webra .91 today with a Graupner 14x11
Muffler-----Davis SoundMaster 90 size
Carb-------MDS 9mm C1 from MDS 1.48
Fuel--------Davis ABC
Prop-------Graupner 14x11 two blade
RPM--------7,550, I could coax 7,680 out of it but that was leaning on it a little too hard by the sounds it made. This is an older engine, ABN I believe. As a glow it would turn an APC 14x6 at just under 10,000.