WOW, just WAAAYYYYY over kill....

I used to use a JR 2721 metal gear and about 90 oz I think on 4.8 v
3/4" nylon arm and horn with metal clevises. You dont need much throw at those speeds only about 1/4" up or down and use high rates when you land. Also another tip be careful not to "Bank and Yank" I hace seen so many plane tip stall and eat the dirt.

Tim