scottlboyd.  I would not rush to purchase a replacement carburetor.  The vacuum secondaries on the Holley carb you have will adjust for the cfm you need for how you drive your 'Bird.

I would not expect to be able to take any new or used carburetor out-of-the-box or off the workbench, install it, and not need to do some sorting out of how it is set-up to assure optimum performance.

I would recommend that you connect with someone who knows Holley carbs and is GooD at pursuing vehicle drive-ability issues.

Hope this helps.    


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

thanks for the reply! The carb I have in there now is of questionable origin-in other words, a friend who had supposedly rebuilt it told me it would work well on my engine. If I keep it, I need to have someone rebuild it properly and tune it properly-neither of which I am capable of doing. That is why I was looking at getting a brand new carb as a good starting place. Holley also makes a list 1848 brand new which is 465 cfm but I believe it has scrubrolet linkage and would have to be adapted for the Ford linkage. My car is almost always on the lower rpm scale-never raced or revved high. Do you think the 390 cfm carb is too small?

thanks for the help

Scott

Redding, California

Is the carburetor known to be in good condition or is the history unknown and it possibly needs a rebuild?
Have you spent time tuning or are you running it in the "out-of-the-box" configuration?

In general, something around 500cfm is a good compromise for a stock engine.  550 is more than it needs but possibly is not too big since it has vacuum secondaries.


Lawrenceville, GA

Hi all. I have a stock 57 Ford 312 engine bore .060 over when it was rebuilt and have been running a Holley list 1849 with mixed results.
I believe this is a 550 cfm carb. I experience idle issues, poor low end performance which leads me to believe that I might have
too much carb. Before I rebuild it, I am considering a brand new Holley 4160/ 0-8007 which is 390 cfm. Research shows that
list 1273 Holley came stock with the engine and was rated at 410 cfm. Engine is 322 cubic inches bored out and is stock in 
every other way (auto trans). The Holley carb selector points to the 390 carb to be the one to use. Any help that you can give
me to make a decision would be most helpful. I don't want to choose a carb that is too small either.

Scott

Redding, California