In my opinion you really should index both valve and ignition timing with the number one piston at TDC on it's compression stroke any other method is sure too complicated for me. With the head off you will have to do this by the correct position of the other pistons with no.1 at TDC to determine if you are on compression stroke or intake stroke. . with the head on TDC on compression stroke can be found by several easy methods.........

William Rogers.........