Since the 150 and 175 are the same block, bore and stroke. What does it take to bump a 150 to 175. How much change in prop pitch would be needed to keep the RPMs down. I think the current prop is a 25 pitch. 6" jack plate. I am currently running 58-61 mph GPS at 5300 rpm with a heavy load. This is on a 04 Champion187 The vmax is 04 also.