Pushrod for hydraulic cam and 273 rocker arms

what does being able to see threads have to do with correct geometry?The longer your adjuster the more leverage on the weak neck between the threads and the ball. If your geometry is right
and no threads are showing and there is no metal interfering with correct operation you should be golden...or am i missing something
I think it's all about having clearance between the cup and the rocker arm. 2-3 threads seems to be golden .