Holley/Demon Carb stumble

Its the holes in the metering block that intersect the main well channel. If they put too many or too large of emulsion orifices the fuel curve through the rpm range can be wonky. Personally I like Holley's old school calibration 2 E holes .028 in size. You have to have a wide band to see if your AFR is doing weird stuff to get a handle on trying to tune them. Best left alone.