Another data point: I'm running a BB Mopar (451) with a 272@.050 cam (.652 gross lift) and 10.3:1 iron heads at the moment. Carb is a 950 with 4 drilled throttles (.100, IIRC). Idles at 13.5-13.8 AFR, 1100-1200 rpm and I think it's reasonably "crisp" whatever that is