Morel sent me 15 photos of "defective" lifters that were sent in for warranty. When Morel designed their hyd rollers in 2002 they found that running a tighter tolerance on the valving to ID of the body would allow for higher continued RPM levels. That tolerance is a minimum of .0001" to .0002".
Now if you your tolerance is in 10th's how can the lifter function when it has this in it? I had an old machinest once tell me swap the L and F in LiFter and you have FiLter.