Jon, when using a carb in a multi carb setup, how should one select them? Is there a golden rule like the displacement noted below?

I am going to put a pair of Holleys (probably 1904s or some other glass bowl single) on my truck, a Dodge flathead. My selection was going to be a pair from an engine around 170 cu in. does that sound right?

I like the holleys because of the cool looking glas bowls, but mostly because of the ease of changing power valve calibration.

Any words of wisdom for me???

Originally Posted by carbking
Al - with no disrespect intended, this question is like many "will it work" carburetor questions - insufficient information.

The Holley 1920 is a model of carburetor. The 1920 is a one-barrel; that is all we know. Different versions of the 1920 were used on everything from a Ford 144 CID to a Ford 300 CID six. These different models have significantly different internal venturi sizes, thus significantly different airflow.

As a general rule, when migrating an O.E. (original equipment) carburetor from 1 application to another, it is not wise to vary the displacement more than + - 3 percent. So if we take 3 percent of 235, we have 7 cubic inches. Therefore you could use a different O.E. carb from engine of displacements 228 ~ 242 CID.

Jon.