MOVE THE ENGINE OVER RIGHT OF CENTER 1/4 INCH AND SHIM SO THE SPINNER IS CENTERED WHEN THE COWL IS ON.AS FAR AS THE DOWN THRUST DON'T REALLY WORRY ABOUT IT UNLESS YOU HAVE A CLIMBING PROBLEM WHEN THE THROTTLE ON 3/4 OR MORE.A FLAT BOTTOM WING LIKES TO CLIMB WHEN THERE IS TOO MUCH SPEED,DEVELOPS ALOT OF LIFT.WITH THE SHORTR NOSE THE RIGHT HAND THRUST IS REALLY WHAT YOU WILL NEED SO GO 1/4 ON THAT