So, I was thinking. I went back to the beginning of your post. The second pic is from the Magnum engine, yes? "Knowing" how manufacturing works, the 3.9 Magnum V6 came with a timing chain tensioner. Now here's where I put too much thought into it. That void would allow oil to spill onto the chain. Reason they did it on the left side is the chain would pull it around and up the other side onto the tensioner slide. If they did it on the right side, the chain would pull it AWAY from the actual tension side. So, if the made this special for the V6, why make two different versions. Just use the 6 on the 8. Idfk.....