Volvo Repair: head replacement, volvo 850, sprokets

Question
i am tring to set the cams in time but have a feeling that the marks on the cam sprokets are not where they are supposed to be and am wanting to know if i can line it up with the back side slots in the camshafts?
94 volvo 850 2.5 non turbo  

Answer
yes but there is the volvo tool used on back of the camshafts  that you have to use to line up the camshafts after you install that volvo tool on the camshaft  if will line them up correct but you need to get the tool from vovo dealer if they let you borrow it .dont try something else it is not worth what you can damage .good luck .