Put it on and try it. I like the 10-7 I'm using on my .46FX. It's a Master Scimitar. I've used an 11-6 and 11-7 APC also. I like them to. Basicly I use any prop that is recomended for the engine and it doesn't make a lot of difference on my LT40. You'll probably ding it up anyways but being a little shorter might help lengthen it's life..