I think most people realize that all power is not the same, a 330 hp Ford Cleveland 351 would not pull an 18 wheeler as well as a 300 hp Cummins. The engine in the right background of this picture is a Webra P-5 .91. It's prop range is 14 x 12 to 16 x 8. That one would turn an APC 14 x 12 at 8,120 on 5% Fox, exactly as claimed,. A few guys tried to run 14 x 6's on them and were quickly disappointed. I tried the 14 x 12 on a Super Tigre .90, it quickly overheated and made scary noises. The MVVS .91 turned it OK but could only manage 7,500. My gas two stroke experience is limited to 3 Maloney 1.25's, a Mustang 50 which is a rebadged Fuji 50, a Zenoah G-45, a Tartan 1.34 and a Merco .61.
Webra P-5 .91 to the right.