Thanks MJD and Av8or48!
I was looking at an earlier post from MJD where he quotes Alan at Weston saying that 8X10 gave the best top speed:
Alan at Weston advised me that the 8-10 gives them the best top speed, and with that prop they said run stock header length. With the 8-9 about 1/2" or so off , and with the 8-8 about 1" off is required for best performance. They also noted that launches with the 8-10 are a bit of a challenge, occasionally they break a prop but most of the time it's okay.
But if Av8or48 has run both an 8X10 and 8X9 against each other in a challenge, it looks like I'll have to bring both props to the field this weekend and see. I'll try and record video and post it (too bad I don't have a radar gun though [
])
Thanks for the input everybody!
-Mike