I get this data from a R/C Report magazine test using a zinger 14x6 prop. R/C Report was located in Huntsville, Alabama where the altitude isn't extremely high so that helps the numbers.
The test showed 162oz. thrust at 9,100 RPM or ten pounds.

My OS Max .52 with a 13x5 in a 7 1/2 pound 1/5 scale cub produces about 6 1/2 pounds of thrust. There is not much up side performance and I have to really get a head of steam before looping it.