Is it that his head is tilted down, or that his eyes are? I have a Dai head on Gang's body, and I have no problems with him... If it's a matter of the head tilted, then try sueding the neck. If it's the eyes, then it's probably because the eyes have high domes and the eyewells are not beveled properly/enough for the size and style eyes you're using. You can fix it by getting low-dome eyes, beveling the eyewells, or by resigning yourself to having some gaps around the eyes and not mushing them in all the way with the putty.