>has anyone here split (cracked) an adjusting nut for the roller rockers ?
I have the Comp Cams 1.6 Pro Magnums for the 7/16 stud and noticed that one of the nuts was cracked staight down the side .
what could have caused this ?

 

Mabye you tightened the set-screw too much.

 

If the set screw is contacting the top of the stud too far down in the body of the locking nut, it may split the side of the unit. If this is the case in your situation, you may wish to consider installing longer rocker studs so that the contact point is higher, within the thicker, hex portion of the nut.