Having an extra set of formerly sludged up and oil caked rockers and shafts for a 3.5, I decided to engineer up an adjustable rocker arm. I cut the top off the hydraulic arm, pressed out the hydraulic guts, then honed the opening to .495", and pressed in a .500" by .75" bushing. That was threaded with a 3/8-24 pitch tap. I used a Crane adjustable rocker screw and locknut and redrilled the oil hole so oil will flow out the top of the rocker just behind the locknut and oil the top end like the hydraulic rocker would.
Now, you may be asking why I would take a perfectly good rocker arm and do this, and to what end. My devious mechanical mind knows that a solid valvetrain can handle more lift, operate faster, and go to a higher rpm without valve float. This is a major advantage when using custom ground cams, since the base circle is reduced to increase the duration, but at the cost of lift. The adjustable rocker arm shaft can make up some of that lift, and eliminate the need for lash caps. Those little rascals are over $100 bucks for a set for our engines. You also have no lifter/lash oil up when the engine is cold, just an occasional valve adjustment. Stay tuned, as I make 23 more of these fascinating little rockers and try an install and adjust on the mighty stroker.