not sure what my prop is 70 or 72. I called and ask for and got one. have to go measure. it's perfect in my opinion. I like to slip hard as well, that's how come I can do the 10ft off the numbers for a base turn and to slow down more on the home stretch I flatten the wings and keep in the hard full rudder until I have the right speed to touch down, than I let go of the rudder and full stick back ya baby. gotta love that fox