How many people do you boat with? If you typically run a full boat your right on the money. Also you mentioned helping your mid range. If mid range speed goes up response generally goes down. It seems only a slight adjustment in rpm is needed if at all. I agree with Griff

Griff is correct. Theoredical rpm changes are 200 rpm losss per 1" of pitch growth. Going to the stock 30 should pull the R's down 400 from the 28 stock propellers. "Standardized Lab Finishing developed by Mercury was a 300 rpm gain putting 100 below the stock 28 current rpm level.

Labbing propellers was always intended for one thing when it was developed years ago. That was top end speed. The ability to turn a high pich propeller at the same rpm as the lower pitch prop netted 1-5 or 6 mph. We have learned however, every boat won't respond the same with the old process. Slip numbers can climb high and mid range can suffer as well as little to no gains on the top end.

Your boat does require a slight mod to the original template. This is actually a good thing since you really only need to gain 200 rpm. One other often understated gain from Lab Finishing is the butter like feel they obtain after the process is complete.

Call us if you have any other specific questions and we can go through the details.

Happy New Year!

Brett