Thanks for the reply efnef. But i don't thinks its a weight shift problem. The majority of my weight is on the inside of my right heel at the top of the backswing, which i thinks alright.
I can swing to the top and keep my head still but i can feel a lot of pressure wanting to lift my head up. I'm sure that if i'm ever gonna solve the problem it's that pressure i've got to get rid off. All i can say is that it feels like my left shoulder wanting to push my head up.
i'm pretty sure it's not a flexability issue as i can practice a 110 degree turn without a club with my arms across my chest and have no urge to lift my head. It seem to be directly related to the lifting of my arms.
I know it would be a lot easier if i had some video, but any ideas would be appreciated.