I am running a Holley 4150 (List #4306 - 735 CFM, Vacuum Secondaries).
With a lot of help from a local expert, my carb is "dialed in" and runs, idles, and behaves great. I just got 16 MPG on a recent trip to / from Phoenix.
The car has been set-up for about a year now, and after it was set up, I haven't had to do aanything at all to keep it running right.
Note that my initial problems really seem to have been electrical (ignition), vs. a carb issue.
If you have access to an expert, the 4150 series carbs can work really well.
Rocky
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