3 different lifters won't stay pumped up

[twfs]

Hi all I have a 87 mustang with a fresh 5.0 motor and ecam in it. The problem I have is a little valve train rattle that I have narrowed down to cylinder 4 on the exhaust. It has been converted over to stud mount rockers and has ford racing 1.6 roller rockers. It started rattling so I went through and adjusted all of them and no differnce. Got a stethoscope and narrowed it down to the passenger side and put on a valvecover that i cut a hole in the top off and went through them while it was running and got to that one and and tightened it down a little and it went away for about 10 or 15 seconds then it started again then I tightened it down again same result got quiet for a bit then started rattling again did this several times. So i came to the conclusion that the lifter was bad. Now I have changed that lifter 3 times with the same results moved rockers around pushrods everything I can think and it does the same thing. What in the world is going on here. I have excellent oil pressure 60 cold and about 48 warm with a mechanical gauge. Any ideas or thought would be appreciated thanks

 

[jtl]

Even though you have good oil pressure, it sounds like maybe that one lifter isn't getting oil to it. Did you prime the replacement lifters before installation? I'm not sure if that is needed or not but you may want to look into that as well. Hope this helps.