Lifters on the 292 are easy to change and not expensive. If its chronic I'd replace them. I would use some Marvel Mystery Oil and run it for a while then change the oil and use Castrol 10W-30 and use some Lucas Addative. Should stop it. My preference is to use System 48 Plus off the net. I use it and have no valve train noise of any other mechanical sound. Just smooth and quiet. Its guaranteed. H.