Please take a look at my thread:
http://forums.iboats.com/showthread.php?t=263601
I am trying to determine if going with a four blade Stilletto prop in a 20P or 22P would help lower my WOT RPM from 5100 to 4600-4700 and give me GPS speed into the 50's from 47 now with my current 19P SS Merc...
I have a 1988 Chapparal 2350SX cuddy cabin with a 350 Magnum 270hp and an alpha 1 lower/ new Sterndrive Eng upper drive 1.47 ratio. The boat came with a Quicksilver Silverado 3 blade SS prop 14x19p (cupped). When trimmed out at WOT it is running 5000-5100 rpm @ 47mph. Last year I did see 48.5mph...
