To tell you the truth I don't know how it changes but I know it works.True,You do it for every cylinder.
The cam card says it will be 4* advance if installed straight up.It just means the cam is ground 4* advanced on a straight up center line.Get the cam degree'd anyway to see if it lines up 4*.If not than you can have it dgree'd at 4* with the correct timing cain gear with the notches in it or set it up with a gear with adjustable bushings.Most good cam company's are dead on though.