The only way to really measure the incidence of the h-stab to the wing is with an incidence meter. You can't eyeball it.
https://www.towerhobbies.com/cgi-bin...?&I=LXET66&P=7
But I would try the balance process first. It is usually the balance, especially if this is an ARF or RTF.
I have to put a quarter on the tail of my Radian to get it properly balanced.