i have a astra mk3 with a x2oxev engine 2llitre is they anyone on here who nos the correct way the cam pulleys s go on as they is a v in them, which says in and ex on both and they can both sit eitherway before you bolt it to the shaft , i cant get it to run properly now since the headgasket has been replaced and its pissing me of now,somebody help me with advice or a picture please .