I have a 27 hp kohler mud buddy longtail and it is time to replace the prop. The mud buddy site recommends a 9 x 7 in general but I was talking with the guys at mud buddy on the phone and they recommended a 9 x 6 if you usually hunt with light loads and want more top end speed. At first this didn't make sense to me because it has less pitch and thefore should make less thrust per rotation but they said it puts less load on the motor and so the rps are higher and you go faster in the high end if you are not loaded down. Kind of like the overdrive gear on your car at cruising speed. I usually hunt just with the dog and only 1 or 2 dozen decoys so ordered the 9 x 6. I mainly use the engine for shallow river running and not bogged down in mud or heavy weeds. Now I am wondering if I made the right decision. Anyone out there with real world experience with similar HP motors and prop selection between the 9 x 6 and 9 x 7? Thanks for any info.