Most of the time, the only occasion this tool is removed my the tool drawer is when there's a problem. Your camshaft, pinion gears, timer gear, breather gear . . . all the marks on the teeth line right up and your cam timing is done correctly? Right? Wrong? The fact is: You most likely have 4 to 5 parts, manufactured by 4 to 5 different manufacturers. A mark could be off a tooth? Throwing everything off . . . Different gear pitches. New parts meshing with used parts. Are your valves really opening and closing at the precise time they should?
This is the best way to do it. Using dial indicators. That needle will indicate movement (what the human eye can't see) You'll know exactly where you're at. Correcting cam timing is done my moving the cam gear on the camshaft (not easy). Also done by changing pinion gears, changing cam gears, moving the cam (+ or -) 1 or 2 teeth . . . or modifying key slots. It's a learning experience every time this tool comes out. Think dammit !