3.0 SC Chain noise yes, no, yes it is, not it's not

[relayswitcher]

'83 3.0L Problem. Wife's car. Sounds like chain tensioner failure. Noise is not constant and on right rear of engine. Used a stethoscope with car running. . Raise back of car and started listening a t #6 with stethoscope on exhaust cover. I get normal rocker sounds. Engine idles fine and revs okay, but the sound comes on the down side of the revvings. Listened in to #5 and same normal rockers tapping away. I could start to hear the noise a bit more at #4, but not like a valve hitting a piston or a loud metal sound. Trust me, I know that awful sound. It's just the rolling sound I hear getting louder, but I figure it's just transfer noise from the right chain housing where the sound is very prevalent. I now listen to that chain housing and it's like someone is hitting my ear directly from the other side of the metal there. ] So I did the thing. Set to Z1 TDC rotor at #1. Removed the extractor and the rear sheet metal cross member. Opened the chain house covers and no failure. How do I know this? There are safety collars on both tensioners and they are NOT laying on the tensioner bodies and chains are tight as they should be. So, my first thought is #4 piston. How? I think oil got low and car got driven fast which is the case I'm afraid. But this does not sound like a blown engine to me. And it runs smooth.... except the rattle noise. Before I do the major thing, I'm going to turn the crank by hand and see of it might be master link chains maybe link is falling off. I already checked the ramps... look good. I thought about putting the new pressure fed tensioners on and close it up again and start to see if noise goes away. Maybe I'll get lucky.
Anyone with clues as to what else could be making this noise. Thanks, R