""I can lean out the idle more but it makes it more prone to stall on braking.""
Radar, I found this same problem when I tried leaning out my in D idle A/F into the mid/high 14's. I would slow down to a stop and my idle would start to fluctuate and I would have to kick the accel pedal to keep it going. After a few stops I richened it back up into the high 13's and it quit doing this.
Good point!
1970 YO7 A66 [Canadian Export] F8 Challenger 340 (Currently in shop for stroker assy.)