It looks like they did their homework! If you look at the parts page for the carb you can get air bleed type jets for the removeable booster clusters. You can fine tune the idle circuit and the shooters for the accelerator pump. Look close and they moved the position of the idle adjusting screws to. Holley screwed up the 4010 design because they used the same booster cluster in the 600 and the 750. The autolite 4100 has booster clusters tuned to each different size carburetor. Holley tried to use the same booster calibration in different size carburetors and it didn't work.

Has any one ever used one of these carbs,wondering how the worked out of the box,for a 351C with a mild cam.