Adjustable Rocker Arm Help....

First, I don't feel the Edelbrock lifters are really good. They have that flat metal retainer instead of a round wire clip on the plunger and that retainer will pop out over time. Last one I took apart had 6 of 16 like that and the engine was running with no noise. You can usually find them hanging around the lifter end of the pushrod. They are no more than a stock non-performance lifter so it does not surprise me that they can be comressed that far. IMO, they should not be able to. However, another thought is the lifter bores. Were they measured? I run a max of .002" clearance. If they are larger than .906" ID it's time to bush them. That has only happened once in the 40 or so I've done after starting to check. But it does happen.