Originally Posted by xpmt
A good substitution is the Ballistic unit. It raises the drive line about 4 1/2" Does this adversely affect flight behavior or is it not relevant?
Yeah, that would change the behavior of the aircraft. If your engine is making 600 lbs of thrust, and the thrust is 4" higher than it should be, then that will create a force that works to lower the nose of the aircraft in flight.
Your canard will need to create an additional 20 lbs of lift when you go from engine at idle power to full power (while in flight). This will create lots of bad issues, such as having to adjust your trim every time you adjust engine power.
Small changes, such as a half inch or so, won't be noticeable.. but 4 1/2" could make your plane a real handful to fly.