Last night I readjusted the valves on my motor. I loosened them all up and retorqued them to 20 ft-lbs. I think that might be a little much, but I can't find any specs on it. So I go to start it and it sounds like I have a solid lifter cam. Something I noticed was that I was able to push some of the lifter plungers down like there was no oil in them. I didn't think too much of since it's been about a week since I started the motor. I have plenty of oil pressure, 40 psi at 1000 rpm. When it gets warm the pressure drops to about 20-25. I never noticed the engine getting tight when I was spinning it to do the valves. So I don't think there's any valve contact. I'm thinking I might have gotten a bad batch of lifters. Any ideas?