Well, even fully pumped up shouldn't the valve close? The other lifters in this engine will compress about 1/8" when you push down on the rocker arms. I have two other sets of lifters and when I put any of those in they also will keep the valve open. I have checked the rocker arm and push rod. I can't figure out why some of the lifters will compress and others won't. All of the lifters are from 92-98 Magnum engines.
