[Mike C]

Originally Posted by PGSigns

Hard to tell from the pics bu it does look like when they cut the head for the screw in studs they also opened up the head for push rod clearance. If this is done you need to have guide plates. There are several lengths of rocker studs and it the ones that are in are for roller rockers they are .150 or more longer depending on the ones used.
Jimmy

This is what I was going to say as well. They removed the “guide” that’s machines into the non-screw in stud heads, then drilled and tapped foe studs. Get some guide plates and readjust valve lash.