TIX: you are right, the B11 has got the same piston sleeve/rod than the Shark 10. The difference between those two are the crankshaft (different timings for better mileage and more torque on the B11) and the cooling head.

rageworks : the difference between those 2 are the weight and the timings. The 01164-14B is balanced on the plate with a small weight that the 01163-14 doesn't have. For more power, I would definitively go for the 01164-14B.