I have a stock-calibrated Edelbrock 1405 (600cfm) on my stock 1956 312. It runs great, seems responsive, pulls pretty hard without drama when I floor it. So, as a baseline, it’s good.

I also have at my disposal an unmodified Edelbrock 1406 (also 600cfm). This carb is supposedly the “economy” version of the 1405, which is for “performance.” It has different calibration internally including various fixed metering orifices being changed relative to the 1405. I haven’t tried it on the car.

I also have a stock 1957-specific Autolite 4100. It is considerably smaller than the edelbrocks—supposedly around 450 cfm, with vacuum secondary.

I will probably try all three of these carbs at some point, just for curiosity’s sake. The Edelbrocks have more calibration options than the Autolite to dial them in, but the Autolite was designed for the 312.

As for objectives, this is a cruiser/driver that I occasionally mash the pedal on just to feel it push me back in the seat. I do like the idea of dialing in whiscruber carb I go with for best performance/economy.

All that being said, which would you choose and why?

1954 Crestline Victoria 312 4-bbl, 3-speed overdrive

If any of those carburetors will be used on your 56 312, and you are happy with the carb that's on it, why do you want to install one of the others?

I suspect you are going to get many different answers to your question.  Maybe it would be some help if I told you about the carb I have and why I chose it.  My Tbird has a Holley 1848-1 465 cfm carburetor on a .060" over 292 with 312 heads and "B" intake.  This carb scored high in the test Ted ran a number of years ago. If you haven't read his article, it's at https://www.eatonbalancing.com/2012/09/25/four-barrel-carburetor-testing-on-the-y/.   The 465 carb is a modern Holley version of the stock 1957 312 Tbird carb.  Nostalgia and memories are important to me.  When I remember my early Y-Blocks, that's the carb I remember.  I don't remember a shiny AFB with an Edelbrock sticker or a Ford 4100. Both are fine carbs, but they just don't look right to me.  My 465 has instant throttle response and pulls hard through the gears.  It's perfectly sized for my Y-Block.  I am sure a 600 or larger carb would be slightly better at higher RPM, but I never twist my YBlock over 5,500 so it's not going to be much help.  The biggest reason I like my 465 is that it's still available new.   I have had more than my share of problems with old carbs and I don't want any more.

I always like reading Teds test results. Too bad the 2 smaller Summits were not included. For top rpm Ted has found a bigger carb is normally best numbers but looking at Phil’s 465 and the Ford 1.08 or 440 I see drivability. Unless kicking mine in the butt it rarely sees 3000 driving light to light in weekend driving. My preference is what gives you the best of “what you want” and for me that’s snappy off the line at the crack of the throttle pedal without flooring it and no hesitation during heavy acceleration like passing on a 2 lane road. My 375? cfm Carter WCFB defiantly gives me that. Good luck 

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Put the other one on and try it.  Not that big a  deal to change from one Edelbrock to another.  Then decide which one is better.


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

In the end, carburetor choice boils down to drivability more than full throttle performance.

Even when the carburetors are the same part number, they may not be equal in performance.  This has to do with manufacturing variances within the carburetors themselves.  An example of this are four new Holley 750 cfm HP carbs that were purchased and were back to back tested on one of the EMC engines.  Not surprisingly there was a 10 horsepower difference between the best and worst of these carbs.  All these carburetors started and idled just fine.  Slight variations in drilled hole sizes, discharge nozzle alignments, microscopic casting variations or flaws, and a multitude of other items can contribute to carburetors of the same part number not being identical in performance.

Lorena, Texas (South of Waco)

Phil’s comment about originality and reviewing Ted’s test reminded me that I also have an original 1957 Carter AFB with vacuum secondary, like the last-place performer in Ted’s test. If I had the Holley I’d have the full set!

I have decided to put together a comparison test of my own for all 4 of these carbs. I’m planning to measure performance as Edelbrock suggests: timing WOT acceleration through a specific RPM range, probably 2500-4500 rpm. For economy, I’ll install a tank selector and run a separate, very small tank of fuel over a planned route and see how far I get before running out. Throttle response and drivability will be evaluated as well, but probably just subjectively. Should be fun to see how they stack up!

1954 Crestline Victoria 312 4-bbl, 3-speed overdrive

The one carb that I have always wanted to try on my TBird engine is a Holley 650 double pumper. I wonder if my car is light enough and my gears tall enough to make this work?  Would it bog, be hard to drive and could I feel any real performance gain?  So far I haven't wanted to know bad enough to invest $600. 

Phil, I think the majority will tell you to stick with a vacuum secondary carburetor for the street. But for kicks, maybe you can beg, borrow, or steal a double pumper. It might be more effective on a ported B manifold/Mummert. If you have money to burn, keep an eye on Holley's factory-refurbished carbs on their website. It's not likely they have one in stock, but you can request to be notified by email when/if one becomes available. You'll save a considerable amount of money, free shipping, and it comes with everything a new carburetor includes, including the warranty.

Good point on the Holley refurbished carbs but if you DO get the email you need to jump quick.  I recently checked my email in the afternoon, found that they were back in stock, and clicked on the website to find that they were sold out again!