273 Style Rocker Arm Adjusting Screw

So as I started to adjust my valves I had a really hard time loosening the jam nut of the rocker arm adjuster screw.

What I have is a mix of both stock style jam screws and jam nuts (see middle picture). I had faced all rockers when I had them out btw.

The ball end rocker screw (see top pic) appears to jam a standard 3/8-24 nut while the nut used is also a jam nut. It explains why I had a hard time getting it apart.

Question is the correct set up for this type of assembly to use only one element (screw or nut) that has a locking or interference fit not both as I seem to have?

In other words the ball end 3/8x24 adjuster screw supposed to have some type of locking or interference fit towards the too? The threads are not damaged look ok. But a standard nut stops tight at the too end away from the ball. Something doesn’t make sense to me.

I am looking to change over to the hardware on the right with the 12 point see last picture. Would that be a standard thread on the ball end screw and a locking/interference nut?

Thanks

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Run a sharp tap through the rocker. Interference fit adjusters were used to reduce costs.

Don’t mix the two types of adjusters, meaning don’t use a straight threaded adjuster in an interference hole and the other way around.