While I am doing some valve work on my 1940 Super, have a hydraulic lifter question. I am ultrasonic cleaning the lifters. Doing a leak down test on each. I noticed on one or two of the lifters they seem to have a good pumped up resistance, but they seem to leak just a bit around the sides of the plunger assembly coming up into the outside spring area. Just about all of them don't leak at all. If anyone knows if the lifter is still usable, or replace? I might also ask what wears out on these, the tolerance on the walls between the body and plunger, or? Thanks