273 rocker arm adjustment

Late to the party...I just fired up my motor finally after almost 20 years. Running kind of crappy so far, Plenty of Oil pressure, some noisy lifter. I'm waiting to see if they pump up but from my recollection and from what I'm reading here, I may have the rockers (hydraulics) set too loose. I'll check that coming up soon but I also see the comments regarding the "notches". I was completely ignorant of that as a youngster so I have no idea what to expect when I look. I do think a young me would have paid pretty close attention to the functional details though; I guess I'll find out!