EQ mag heads. the comp cams rocker studs 4504-16, the lower 5/16 stud length is .680" and the Lunati 86004-16 studs have a .750" lower 5/16 stud length. these are quality black items (grade 8 or better I would think). I have both sets cuz I needed more upper (above the boss) (3/8) thread length to get my geometry dead on & the Lunati has 1&3/4" up top & the CC has 1&1/2" up top. My 1&3/4" installed height (.100" longer) valves are giving me setup problems & even the Lunatis I might need to shim them up off of the head bosses. My Question is: how much thread engagement down below into the head bosses must I keep to have the max strength against breakage (5/16 coarse threads). I can shim up the Lunatis to how much the CC ones are (.070" gain) which will get me "close" but I may need a bit more so I am wondering how much actual length does that 5/16 stud need for max strength? so I ain't risking breakage especially with these smaller 5/16 studs. thank you for your time.