Perhaps the Pantera crowd is more knowledgeable than others, but I've found that not many know what their idle mixture actually is. The engine can be quite insensitive to mixture screws if you are looking at revs and vacuum, and it may not sound really any different if you are that much off with mixture. It's just not always that easy without AFR meter.
It's not uncommon either to some guys try to save a little gas by leaning the idle out some, when they really should try to tune the transfer slot with air bleed and idle fuel restrictor, or main jet and PV restriction, or main and respective air bleed, depending where in the fuel curve the work really needs to be done. However that's difficult to most for several reasons.
My 16:1 idle trial was on a road trip, tuning the 1050 ultra hp dominator on my 12.3:1 compression, pump gas stroker small block with super victor and mech roller. Probably an insane combo to try to make run nice on the street, but but it does work very well these days and has been a learning experience. Gotta admit I like the easiness of almost stock engine in my Pantera these days. LOL.
Here's a pic from that trip in 2008
You can even see the dizzy manifold vacuum that caused the idle speed issue. 