The venturi is a portion of a carb barrel at which the cross sectional area diminishes. As the column of air enters the confines of the venturi it speeds up, and Bernoulli's principle states that ...

In 1974, the 4300 was replaced with the 4350. If you study a good cross section of 4300 carburetors from 1967-’73, you will find there are significant engineering changes every year. In 1967 ...