I am at 5000 ft and the YS 63 pulls my plane great.Around 1/2 throttle for hover.I used the stock fuel tank and so far no problems-30 runs or so.The vertical stab should be 90 degrees to the horizontal stab-if not lightly sand the slot till right.As far as servos in the tail I used HiTec 925mg all the way around.The plane CGs at 5 1/2" with a 1650 Nimh battary under the fuel tank.Also used a True Turn 2 1/4 inch spinner with the wide blade cut.Running a APC 13x4 wide blade.Great prop for the 63 runs at 11300 rpm at this elevation on 20 20 fuel.Also I would upgrade to 4-40 hardware to get rid of pushrod flex.Otherwise enjoy it is a great plane.