I am repowering my 2002 247 grady advance with a four stroke 250 yamaha. Has anyone done this and if so can you recommend what prop. Grady White sent me the performance sheet for the 257 advance with same power. It has a 15 1/2 x 17 3 blade SS prop. I am interested if I need a pitch 19 on the slightly smaller boat or even a four blade for better hole shot. I am aware that the boat would probably do better with even more power or twins but that is not an option, thanks a lot.