I am replacing the head gasket seal ans have now got to reset the rockers. This is all new to me and I have no experience at any of this just working through it. I need to rotate the crankshaft and start with number 8 valve fully open. How do I turn the crank, how do,I know when number 8 is open and which one is number 8. Front or back. Simple stuff for many of you I know but I have no clue any help would be great