Back in the day, I had a new Carter 750 Comp series AFB on my stock port 906 headed 67' GTX running 12.2-3s in the summer heat at the strip and idling like crap. My buddy brought along a untouched Holley 850dp, which we swapped on to the GTX. For the rest of the day the car ran 11.80s and would idle without dying like the Carter would.