preferred 2 barrel Y-block intake manifold?

[scicala]

True, but since there's no such thing as a 3-bolt "bugsprayer" carb suitable for use with mechanical advance, you might as well just say the 3-bolt intake manifolds are load-o-matic. Or maybe you wouldn't. But I do.
Technically, though, you are correct.

I agree. We're both correct. Two ways to look at it.

Sal

 

[scicala]

Thanks for the site info. I'm looking for the preferred 3 bolt design.

The highest air flow 3 bolt Holley/Ford carb is the '56 for the 272 engine.
It has the 1 1/16" venturi's like the '55 carb, but is also has larger throttle bores in the base.

Sal

 

[dmsfrr]

... I'm gathering parts for a '56 F100 rebuild and want to install either a 292 or a 312 Y-block ...

While you're pondering all your other choices, something else to keep in the back of your mind...
The Fuel & Temp gauges in a '56 are originally one-year-only parts. The '56 Temp sensor is a larger size than the '57+ versions. You may need to change the Temp sensor bushing in the head to the larger thread size (3/8 NPT) or tap & re-thread the bushing if you use '57+ heads.

The '56 gauges & sensors are spec'd to work on a full 12 volts. '57+ uses a small dash mounted voltage regulator just for the gauges (approx 7v). They won't work correctly mixed together.

 

[Daves55Sedan]

The highest air flow 3 bolt Holley/Ford carb is the '56 for the 272 engine.
It has the 1 1/16" venturi's like the '55 carb, but is also has larger throttle bores in the base. Sal

That's correct. Those are Holley 2110 or ECG carb and they have automatic choke. That was the last year for the 3-bolt "bugsprayer" carb and last year for load-o-matic system.

 

[cokefirst]

I am restoring a 1956 F100 with a 272 and the original 2 bbl carburetor. These truck are geared low for power and not for speed. I wanted my truck to run down the highway at 65+ without spinning the engine at 3000 RPM. I found that putting on dual exhaust rather than the cross over tube made a world of difference. I changed my rear end to a 323 ratio using my Fordomatic transmission. I expect to be running at about 23-2500 at highway speeds. easier on fuel, and the engine both.

 

[cars2cool]

The highest air flow 3 bolt Holley/Ford carb is the '56 for the 272 engine.
It has the 1 1/16" venturi's like the '55 carb, but is also has larger throttle bores in the base.

Sal

So I should be looking for ECG code intake manifold and carburetor? Does the distributor use the same 3 letter code?

 

[cars2cool]

I am restoring a 1956 F100 with a 272 and the original 2 bbl carburetor. These truck are geared low for power and not for speed. I wanted my truck to run down the highway at 65+ without spinning the engine at 3000 RPM. I found that putting on dual exhaust rather than the cross over tube made a world of difference. I changed my rear end to a 323 ratio using my Fordomatic transmission. I expect to be running at about 23-2500 at highway speeds. easier on fuel, and the engine both.

Keep us up to date on how this works out, I'm sure there are a few others contemplating this as well.

 

[scicala]

So I should be looking for ECG code intake manifold and carburetor? Does the distributor use the same 3 letter code?

The '55 and '56 intake manifolds for 3 bolt two barrel carbs shold both have ECG-9424 casting numbers followed by an A, B or F. The only difference I'm aware of is the '56 intake having a hole for the choke warm air tube, since '56 switched to an automatic choke.
The '55 272 two barrel single diaphragm distributor should say on the tag FDJ-12127-C. The '56 272 single diaphragm distributor shoud say FDS-12127-A. Either is good.

'55 carb will say ECG5 on the side of the bowl. '56 will also say ECG or ECG6 and will have an automatic choke on the top cover.

Sal

 

[cars2cool]

Thanks to all for the great information passed on in this thread.