Hi mr. scale, I also have a stinger 120 with a us41 in it. I have been flying it with a zinger 18-10 prop. It flys good but not a lot of vertical. My stinger weighs 16 lbs. dry. I have been thinking of trying a 20-8 zinger. How do you like your 18-12 a.p.c. prop. Mine likes to keep flying on the 18-10 and wants to land a little hot. I would like to know if you have a problem slowing for landind with the a.p.c, Thanks Wayne