Problem being I never checked it hot when the noise starts and now have the coils and valve covers back off which is not an easy task. I was expecting the rockers to be loose, but again, it gets loud when it's hot. So the head expanding makes more sense. I just thought it would be interesting for some to know the preload has changed for morels. I have the cheapest option of lash caps coming, .040 and .080 if I find that number. Still not ruling out oil pressure.
That sounds like some darned good oil pressure! My racing 5.7 has the high volume Melling pump and with 10w40 oil I get about 75 psi on a cold startup. I would love to see 80 to 85!