Hello all I have been nosing around on this forum since I decided my project would be Y block powered and I am amazed at the wealth of knowledge here and am looking forward to benefiting from it.  
As my first post I would like advice on some appropriate carb choices for 292 powered Model A.
The specifications for the car and the engine are the following:
Model A coupe on 32 frame ,Top loader 4 speed trans, 9" traction lock with 3.50 gear
Bias ply 4.50'x 16 in front &.7.00's x 16  on the rear 31 inches tall
estimated weight 2700
292 C1AE block .060 over
Block heads and crank ,magnafluxed, hot tanked, and surfaced where needed.  
heads are ECL fitted with larger valves,new seats,and guides,       
Pistons, rings, bearings, cam, springs, and lifters from Mummerts
pistons are stock type, cam specs are duration 270 @ .020, 234@ .050,lift .465, and separation  of 108
valve springs  are Mummerts recommended VS 105
The rods were reconditioned and new bushings installed
New ARP bolts for the heads ,mains and rods
The intake is a stock Ford ECZ-9425 B
Distributor is a COAF 12127-A ( also has B9AF 12131B marking if that means anything) with a Pertronix module 
The rocker arm assemblies are rebuilt with new shafts and springs.and the rocker oiling holes were cleaned   
The rockers are ECG 6564
spark plugs choice is Motorcraft  BSF42C  gapped  to 35 
and finally will be using an inline PCV running from a Thunderbird valley pan with the rear road draft tube hole 
the long block was assembled by a friend with lots of engine building experience just not on Y blocks mostly FE's
I intend to drive the heck out of this coupe with lots of highway miles and around town cruising. My goal is to have a reliable , good sounding , motor with some low end power ,reasonable gas mileage and no intention of racing on the street or the track  
As stated up front what do you guys recommend for a carb and does anything in this list of parts stand out as the wrong choice to be used with any of the other parts? 
Thanks in advance to all who respond.     

Your favorite brand, 500-600cfm, vacuum secondary.

If you can afford it, I encourage you to experiment and try a few carburetors.  Sometimes one that should be big enough doesn't work out so well and another that is too big works great.  The only way you know is to try it.

The best thing you can do is contact a carb manufacturer with your engine specs and see what they suggest.


Lawrenceville, GA

The stock Holly off of a '57 312 would also work well. I think they are around 450 cfm and have vaccum secendaries. The 500 would also be a good choice.

Reading what you intend for the car, "low end power, gas mileage and not raced" I doubt the engine will see a RPM that ever requires a large carb. I have a similar 292 in my Ranchero that weighs 3700 lbs and rarely sees over 4000 rpm and found it runs great with just a Holley 390 cfm and a minor main jet change to a little larger jets. But asking a question like this is like asking what colors socks should I wear :-). you will get a dozen different opinions.

It’s not necessarily about the size of the carburetor but in how well it meters the fuel.  The advantage a four barrel carb has over a two barrel carb is that additional increase in cfm that’s needed in the upper rpm ranges without sacrificing drivability in the lower rpm band.  Many people forget that a four barrel carb does much of its running around in two barrel mode which is generally smaller cfm wise than many oem equipped two barrel carbs.  That is why a properly tuned four barrel carb can get better fuel economy than a two barrel carb.
 
As a general rule, when selecting a vacuum secondary carb, always select a size that would appear to be larger than needed.  The nature of vacuum secondary operation has the secondary blades only opening the amount needed based on the air demand required by the engine which makes an oversized carb always being optimal in size and never under-carbureted.  The older formulas for calculating carb sizing are geared towards stock engines with no modifications.  Once head porting, better exhaust systems, improved intake manifolds, and larger camshafts are throwed into the fray, then those calculations tend to push for undersized carburetors.
 
I’ve have extremely good results with the Summit 750 carbs on lightly modified Y’s with those carbs having good driving manners in the lower rpm bands and then good power outputs when the engines are stretched out a bit.  The best of both worlds there.  I have the Summit 500 vacuum secondary carb on a warmed over 272 in a ’55 Ford and while it’s a good driver, it is could use some more cfm when getting more aggressive into the throttle.
 
Here are some links giving dyno testing results for Y’s using 750 cfm sized carbs.
http://www.eatonbalancing.com/2015/05/01/unported-iron-heads-can-still-make-over-a-hp-to-the-cubic-inch/
 
http://www.eatonbalancing.com/2012/12/08/milling-heads-for-a-horsepower-gain/
 
http://www.eatonbalancing.com/2012/09/29/a-tale-of-two-330-inch-y-blocks/

Lorena, Texas (South of Waco)