Thisis very helpful, thank you! Now I'm making sense of what I'm seeing. And clearly, if my goal includes preserving the engine, then a lean condition is the last thing I ever want - so the return line seems vital. Thank you for this understanding. I found the below pic on the FBBO forum, showing exactly what you're saying. If anyone has other pics to recommend as good practice or vintage appearance, I'd appreciate it. Now for some forum searches on recommendations on regulators.
https://www.forbbodiesonly.com/moparforum/attachments/dominator-jpg.303429/
