Snoopy1
640cc Uber Pimp
If your 120 is anything other than the original F-120......(120AC, 120NC, 120SC, 120FZ ) Then a 17x8 APC will have no problems hovering 10lb 3oz. Won't be "foamy like" but will have positive control and authority. I also recommend at least 20% nitro. But 30% does give a noticeable boost in torque especially at throttle levels during hovering. Just don't run it lean or it detonates real bad.
Thanks for all the help. I believe it is a YS120 SF and it is running on 20% nitro. You are correct about running lean learnt that a number of years back with the engine it destroyed a brand new TT spinner. It back fired and blew everything off , lesson not do again.