Re: Prop Size?
You can keep the 28" diameter but should need to drop the pitch when going from 3 to 4 blades. I believe the 46' with 8v92's use a 28x30x2.5 4 blade wheel but don't quote me on that. Since you both have 2.5 shafts, I assume you both have 8v92 boats. If you both have 650hp 8v92's with the normal 1.5:1 gears, you should have a good mach. Talk to a good prop shop they should be able to give you more accurate info based on what you have now and what your performance is. I have both 3 and 4 blades for my 46. The 4 blades run a lot smother. Good luck