As far as I know the OS 50 will fit with the Ergo 46 mount, which will fit the Venture. But you need a longer tail boom and blades (Also Ergo 46)... even then you have to tone down the throttle curve (no 100%) or you'll overspeed the head. I think Andy @ Aerohobbies told me the fastest he felt was safe for the rotor head was 80% throttle at full pitch. Perhaps an OS46 would be a better fit.

Phoenix