The "UC" mark on the flywheel will allow you to find an accurate TDC position, but it's only accurate for two cylinders- - - -#1 and #6. Getting the other 4 cylinders exactly on TDC is a wild guess situation unless you use something like the "companion cylinder" method of assuring the cylinder you're adjusting is actually on the base circle of the cam. I've explained that so often my fingers cramp up just at the thought of doing it again- - - - -do a site search for "Companion cylinder valve adjustment"!
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!