From its earliest beginnings in 1902 as an automobile manufacturer, Holley has been all about creating carburetors that offer a greater level of performance. Half a century later in 1952, when the first four-barrel carburetors were introduced to the market on Cadillac V-8s. They were the Carter WCFB and Rochester 4GC and found their way onto Chevrolet passenger car V-8s as a performance option when the 265-inch small-block engine was introduced in 1955. The four-barrel Power Pack option included better flowing "pyramid" heads with a 9.5:1 compression ratio compared to the standard 8.5:1 compression ratio equipped with a Rochester two-barrel carburetor. On the other side of the fence, Ford offered a Holley four-barrel carburetor as a performance option for the Y-block V-8. In 1956, Ford was the first manufacturer to introduce light-duty trucks available with a high-performance engine option. Surpassing the '56 Chevy trucks, offered only with a detuned version of the passenger car 265-inch V-8, Ford made the larger 272-inch Y-block engine available in three stages of tune. The standard option V-8 is known as the light-duty 2V 272 (two-venturi, two-barrel carb), and the truck's original engine can be identified by locating a V in the VIN number on the aluminum serial number tag held on with four Phillips screws located above the lower hinge pocket on the driver side. If the tag is missing, as they often are, look for the VIN number stamped into the topside of the passenger-side framerail right in front of the firewall. If all else fails look at the VIN number printed on the pink slip (title).
Swapping out an old Holley...
Swapping out an old Holley carburetor for a new one is easy with a Holley direct replacement carburetor, such as Holley's new quad intended specifically for small-displacement V-8s and larger V-8 dual-quad applications.
Next up is the Z code heavy-duty 2V 272 identified with a Z in the VIN number. One might suspect heavy-duty means the engine has a heavier bottom-end, but as we've been informed it refers to larger-valve cylinder heads with better porting. Top of the line is the R-code 4V 272 equipped with a Holley four-barrel carb and the good heads. Of course the odds of a '56 Ford pickup still having its original engine are slim, but in the case of our one-owner Barn Find '56 we know the pale Ford Yellow short-block is the engine that came in the truck. Since there's a V in the VIN number, and the heads and four-barrel intake are factory painted in an original 292-inch Y-block Red we know the R code upgrade was added at a later date by the original owner. We've yet to discover a real R-code '56, so they must be rare, but it's interesting to note there never was a letter or digit in the '56 VIN to prove a truck with a Big-Window cab came from the factory that way.
What all of this has been leading up to is we decided to swap-out the vintage "square-bowl" Holley four-barrel carb we inherited and slap on an Original Holley Performance 390-cfm Four Barrel Street Carburetor. The new Holley is the best way to gain extra horsepower, get better fuel-economy, and lower emissions for any application that requires a smaller four-barrel to ensure it won't be over-carbureted. Read on and we'll explain what the benefits of the square-flange model 4160 Holley are for the Y-block Ford engine and how we went about installing it on our 272.
Since the Holley square-bowl's...
Since the Holley square-bowl's power valve was leaking gas externally and most likely flooding internally as well, we figured it was a good excuse to step up to a more modern carburetor.
The first step was to disconnect...
The first step was to disconnect the throttle (gas pedal) linkage which was easily reattached to the new Holley 4160 because it is engineered to be a direct-replacement for the Ford Y-block engine.
Next, the four 5/16 fine-threaded...
Next, the four 5/16 fine-threaded base nuts on the square-flange Holley were easily removed with a Craftsman open-end/box ratchet-wrench.
After the neoprene fuel line...
After the neoprene fuel line (black hose) was removed by unscrewing two stainless steel hose clamps we were able to slip the box-end over the steel line and turn the fitting without rounding-off the flats.
The next line to disconnect...
The next line to disconnect was for the vacuum supply to the stock Ford distributor with vacuum advance. The Holley 4160 has a timed spark vacuum source that was reconnected to the distributor.
Notice the new Holley 4160...
Notice the new Holley 4160 at left has smaller venturis than the old square-bowl Holley at right. The smaller size venturis create higher velocity at lower speeds and produce better low-end throttle response.
A quick, light tap to the...
A quick, light tap to the old Holley separated it from the base gasket and then it was lifted straight up to remove. We were very careful not to scrape the old gasket into the intake manifold.
To guarantee none of the old...
To guarantee none of the old gasket material fell into the engine via the intake manifold we used a wet-and-dry industrial vacuum cleaner to suck away all of the old chunks.
Notice how using a single-edge...
Notice how using a single-edge razor blade to scrape the cast-iron manifold's deck left a perfectly flat surface to mount the part number 0-8007 Holley 4160 square-flange carburetor on.
Before mounting the Holley...
Before mounting the Holley 4160 we installed the new base gasket that Holley includes in the box. For spare fuel pump, carb, and assorted Y-block gaskets we looked to Egge Machine in nearby Santa Fe Springs, CA.
To guarantee a steady supply...
To guarantee a steady supply of fuel-pressure we installed an exact replacement mechanical fuel-pump from Dennis Carpenter.
To guard against fuel-starvation...
To guard against fuel-starvation at higher revolutions we used a Fram G3 inline fuel filter with 3/8-inch openings and stretched 5/16-diameter fuel lines over with the aid of Royal Purple Maxifilm.
The hose clamps included with...
The hose clamps included with the Fram fuel filter looked pretty clean in comparison to the ordinary stainless steel hose clamps we took off.
Note how using Visegrips instead...
Note how using Visegrips instead of pliers made it easy to install the Fram clamps.
Notice how rolling the Fram...
Notice how rolling the Fram clamps over provided a clean look. The Holley 4160 uses an omni-directional banjo style fitting for the fuel inlet, so we positioned it at a slight downward angle allowing an unobstructed path.
Holley recommends tightening...
Holley recommends tightening the hold-down nuts evenly to 60 in-lb. (5 ft-lb). To ensure the 4160 didn't loosen up we used Nyloc nuts in place of the mixed nuts that came on our truck.
It was pretty exciting when...
It was pretty exciting when we fired the 272 up with the new Holley 4160 on it. Instantly we noticed there wasn't a rich exhaust gas smell or noticeable exhaust smoke, and the 272's throttle response was much better.
hen replacing a carburetor...
hen replacing a carburetor or changing the jets, it is a good idea to install new spark plugs. We swapped out the gas-fouled Champion plugs for Autolite 46s with a better reach. The Autolite plugs look like they will resist fouling better.
A Snap-on plug-gaper was used...
A Snap-on plug-gaper was used to adjust the Autolites to stock Ford specifications.
To combat galling normally...
To combat galling normally associated with Ford-style tapered-base spark plugs we used an anti-seize compound. Ford owned the Autolite brand from 1967-1972. We thought you'd like to know that.
After we drove the '56 around...
After we drove the '56 around for a few miles we pulled the Autolites out and checked them for color. Unleaded gas makes spark plugs harder to read, but you can get an idea.
Since the original Holley...
Since the original Holley was leaking raw gas into the engine it was necessary to replace the oil filter with a quality brand. Note the 272 has been converted to a spin-on type oil filter.
The relatively fresh Royal...
The relatively fresh Royal Purple oil was contaminated as well, so we dumped it (not into a sewer or stream) and refreshed with new oil. Now that the 272 runs leaner the oil won't have to be changed as often.