I have a worked 17 Pitch viper, tip cup added, and pitch corrected to a true 17, by myself i can turn to 47 mph and 6400, If I stay at 6000, I run 45-46, speeds are gps. still had a little more trim to go up a but rpms were getting too way to high. Found a Turbo Flats IV, on Ebay, 13 1/4 x 19, 4 blade, will I be able to turn this? Opinions? This is on a fish and ski. Will I lose too many rpms, 400 for 17 to 19 pitch, then 100-200 for foing from 3 blade to 4 blade. What will happen to my holeshot, going up 2 inches, but adding a 4th blade?