I was just going by what the website said . It said 15x 8 or 17x 6 . Well I have a 18x 6 or a 14x 10 I can use. Like you said using a smaller prop ... More pitch. Well 15x8 is a smaller prop and more pitch than a 17x6. I'll go with the 18 x6 I have room for it. And thanks...... Ron