If he wants to make a SWAG at the timing, shade tree methods work fine. There's a lot of variation in factory tolerances. Some people are satisfied to get a hit in the ballpark- - - -some of us want to hit a home run.
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!