Revolution 4 (14 5/8" or 14.6" diameters) was designed for a V-6 gearcase with a 4.8” diameter. It offers outstanding performance qualities for waterskiing, carrying heavy loads, high-current, and or for rough water conditions.
With engines gaining more horsepower, Mercury came out with a 5.44” diameter gearcase for durability purposes while still offering the 4.8” diameter gearcase (225 HP – 300 HP).
For 300 HD (Heavy Duty), the only choice is the 5.44" diameter which is a 14% diameter increase. In theory, Mercury Racing created a larger Revolution 4 prop for the increased diameter 5.44” gearcases called the VENTERA with a 15” diameter.
In summary, the VENTERA with the 15” diameter will keep the same good performance qualities as with the Revolution 4 props, only doing so on the 5.44” gearcases.