[Destroyer]

Originally Posted by THEFERMANATOR

Careful with changing pitches when going from stainless to aluminum. New aluminum props are now being built slightly different to account for this. I've done a few swaps recently, and actually found teh WOT RPM's went down some with an aluminum of equal pitch because it wasn't as fast on the top end due to the extra blade thickness. Get the engine height correct first, but also keep in mind engine height may need to be changed according to which prop you run as some like to surface whereas others need to be buried. And find a prop shop that will work with you. I know my local prop shop will swap out props for a small fee if it isn't the right one so long as it is still in new condition(no scratches or chips in it, or cavitation burns).

There's a local marina at a lake (Budd Lake) by me that has a wall full of used but good props. He'll let you take any one of them and try it out for free so you can find the right prop for your particular engine/boat combination. I wasn't aware of the new Aluminum props, but in retrospect it doesn't surprise me. Manufacturers are constantly changing products to make them better/cheaper/more fuel efficient, etc. Regardless of what kind of prop, if you have a dealer that will allow you to swap out props, I still think that a 17P is a good place to start to establish a baseline for performance for a 150 hp engine on a V20, and then adjust from there.