ft bushwacked

Hello there! I live at 7000FT elevation and all my FTplanes fly like a rock... my FT bushwacked weighs 490 grams W/O battery and its brushless motor is a hexTronik DT750 Brushless Outrunner 750kv and 35amp esc i also fly with a zippy 2200mah 20c.. adding more power up here is a must but i was...