Hughes "retro fit" lifter not pumping up!

Yep they are pretty simple. Take the good one apart and see if the parts inside are put in the same way in the 'bad' one. A check disc might be flipped over or something simple like that. No air going into the bad one from the lifter bore hole does not sound right. BTW, I assume there are the ones that have a machined 'waist band' all around....

I don't know if you noticed this, but the oil holes from the lifter gallery into the lifter bores can be smaller in some areas versus others This is because the finish drilling of the galleries is done deeper and deeper in the galleries with progressively smaller drills. (To make the machining easier). Any smaller hole from the lifter gallery not reach as high up on the body of the lifter and might not be getting oil to the waist band on that lifter. Just make sure that the waist band on the 'bad' lifter is reaching the oil gallery hole in the lifter bore during part of the lifter stroke.

And my son's 340 block did not have part of one lifter gallery finish drilled at all, and the holes from the lifter gallery into the bores were REALLY small in that area. So odd things can show up ....