A few people have suggested changing the thrust line to fix the elevator trim, but I'm going to caution you about that. The point of tuning the thrustline is to center the thrust on the plane's drag so that changes in throttle don't cause changes in pitch. A bit of confusion can come in the situation because speed can cause pitch changes too, which is not a thrustline problem. The way to check the thrustline is to get trimmed for level at full throttle then chop the throttle. If you get a pitch change in the first second or so, adjust the thrustline in that direction. So if it pitches up, you need to angle the thrustline up and obviously if it pitches down you need to angle it down more. The opposite test will verify your results, letting the plane get slow and then observing what happens when you suddenly gun it. Yes, a thrustline that is off will affect elevator trim a little, but tuning it is all about having the plane not change pitch with throttle. Once you get the thrustline right, you can then really know if you have a wing incidence issue.