For those that might be interested and to document our findings. Following the above discussion, the shop repitched our 16" wheel from 11" to 12.5", as they weren't confident to go further based on age and condition. We definitely saw an improvement in speed at the lower RPMs as anticipated, however, it also introduced some cavitation around 2600-2800 rpms. I hypothesize this is due to slippage, as the propeller wants to progress further in the water, but the boat isn't allowing, as I notice an improvement with winds abaft. In any case, it's been performing well otherwise, with better performance at the lower RPMs but still room for improvement overall. Thus, after a long interesting discussion with Kelsey at West by North (Campbell), we opted to replace with a 17x11 Campbell prop on our upcoming haulout. This should give us more thrust with the size increase and performance improvements with the propeller type, as I understand a 16x12.5 Michigan wheel is approx. equivalent to a 16x10 or 17x9 Campbell. As mentioned earlier in this thread, the Perkins has the power to handle a bit of load, and with our trans gear ratio, there is quite a bit torque available at the shaft. After all the theory discussion, looking forward to see the outcome in practice.