I know zip about fords so bear with me...

Friend has a 68 mustang w/351windsor (not original) and unknown heads. Anyhow, a rocker stud broke on the #8 cylinder (second rocker from the rear) and I am wondering if they (studs) are pressed in or threaded. I am guessing they are pressed because there is no "nut" just a straight shaft.

They are non-adjustable, "rail" type (correct term?) cast rockers. So, should we pull the head and bring it to a shop or can the stud be changed in the car?

Let me know if more info is required.