I'd have to check my prop as i switched it out 2 years ago when the original one got scuffed a little... i still keep it as a spare though
![Wink :wink:](./images/smilies/icon/wink.gif)
If you're not buying a $400+ ss pro most marinas won't let you try different aluminum props which kinda sucks... i too don't have a tach so figuring out if i'm getting the best performace is hit and miss. You therefore have to be careful switching as you may end up going over the max rpm for the motor.
Perhaps another option is a composite prop that allows you to change blades out... but it really boils down to price... as MT says sometimes it's not worth the $$$$