Wait a minute. First of all, how did you have the airplane set up when checking the incidence? You can't just sit your airplane down on the ground and slap the meter on - you won't get a valid reading. Secondly, are you sure the airplane's climbing problem is even related to incidence? The way you're testing during flight does not isolate a potential problem. For example, if you suspect an incidence problem test it with the engine at idle. That way you won't have any thrust issues skewing your incidence test. Isolate, isolate, isolate. Next time you fly it, try this. Get nice and high up and enter a power off dive - straight down. Now let go of the controls. What does the airplane do?

It could also be a thrust problem. Fly straight and level and cut the throttle. Does the airplane abruptly make a pitch change? Changing the thrust line on the airplane requires a retest of many other things - especially incidence.

Now, what exactly do you mean by "requires a lot of down trim." When you have it trimmed out what does your elevator deflection look like (about how many degrees from neutral)?