Adjust valves

Never had a problem with 273 rockers. The most I have on a set is 400,000. I've adjusted them 2 or three times, including startup. They are either tight or not. If loose then your fix is good. My max lift is .500. I have no experience with more than that.
I know to put it on tdc but i don't understand about rotate it 90 degrees how do you do that without a degree wheel
I have done it this way, but requires to much turning of the engine by hand. I'd rather use the EOIC method.