Frist thing is get a shop manual it has complete instructions on taking the head off and reinstalling it and You will need it to reassemble the rockers ,I would pull the head it's not that hard and than take the valve out and see whats going on for a few hours work you could have a more dependable engine ,yes you need to remove the rockers than remove the pushrods than all the head bolts than you can lift the head off , do you have the intake and exhaust off ? If thats not done than thats all got to be removed to just take you're time ,But get a shop manual if you can'nt get one they are on the web at Old car and truck project I believe and you could print out the pages you'll need.
Pete
