The Autolite 4300 carburetor was introduced for 1967 as an immediate replacement for the 4100 ... When you mash the throttle and the secondary throttle plates open intake manifold vacuum acts ...

You could say the same thing about a 780cfm Holley 4160 for the Boss 302 or an Autolite ... throttle was opened to eliminate hesitation. Although we will get arguments from Holley fans, the 2100 ...