I have a very faint squeal, howl, whatever you call it coming from around the #3 or #4 cylinder. It is very faint but I don't recall hearing it before. I have Lunati rollers lifter installed. It's a '66 427 solid lifter block so the only oiling is splash. The sound is a revolution type sound and the only revolving parts are the lifter roller. The noise sounds close to the valve cover. I keep asking myself would it be the roller on the lifter despite being shielded deeper in the engine? Not sure what I'm asking, just opening the discussion.
I have the Fairlane Club National Meet coming up in two weeks. The one activity I'll probably drive it. I expect to put about 75 miles on it. So it's not coming apart until after then. I just put over 200 miles going to Carlisle two weeks ago so I'm not too concerned at the moment.
Here is the Lunati lifters I use.