That's the factory service manual method that's been around for 50+ years. It works best on stock engines that don't run a radical camshaft grind. I've probably outlined the actual "companion cylinder" adjustment procedure at least 50 times over the past several years, so the forum archives should have plenty of references to it by doing a search.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!