Well the LongEze has a high thrust line and is a pusher to boot. So if it is pitching down at higher power you want to angle the thrustline upwards to induce some tail down and nose up torque.

It's pretty tough to figure out how much change you need without a really BIG amount of fancy math and knowing the drag centers of all the stuff and how your stability margin is set and likely the phase of the moon to boot. The big boys at Boeing and Mcdonald Douglass would do it that way (without the moon bit) but for us simple modelers it comes down to a "try and see and then do it a bit more or take some out" sort of deal. Just don't patch up any alterations to the cowl until you're done. Or better yet run it without a cowl or with a test cowl if it requires the cowl for proper airflow around the engine. Get the thrust line set up correctly so the tendency is to slightly climb as you add power. Then fix up all the pretty bits so it looks nice again.