Best Carburetor for Chevy 305 in 2021 – Top 5 Picks

best carburetor for 305 chevy

Hey, grease monkeys!

Looking for a carburetor for your Chevrolet 305?

You have everything you need down here.

Getting a carburetor is easy if you know your requirements and talking to the right person. Reliable reviewers are important here because there are many things about carburetors that the spec sheet will not show. You have to rely on mechanics that are in this field for years.

Here, we have explained our experience with five of the best carburetor for 305 chevy. We have also detailed everything about a carburetor to prepare you for the market.

What size carburetor do I need?

The primary formula for finding the optimum size of carburetor for an engine is-

Where,

c.i.d= Engine size (cubic feet)

RPM= Maximum engine rotation per minute

VE= Volumetric efficiency

The values of these for the Chevrolet 305 are-

c.i.d= 305

RPM= 5000

VE= 85%

So, our required carburetor size for this engine is 375 CFM.

Now you might want to round that up to 400 CFM, but this category of carburetors is not that common in the market. That’s why most leap up to 500 CFM. People also go as far as 600 or even 750 CFM. But I tried to avoid the extremes as much as I could.

Top 5 Best 305 Chevy carburetor review

Holley and Eddy dominate the carburetor market for Chevrolet 305 engine. And they are doing very well in this category as well. That’s why four of the five are from these manufacturers.

1. 1404 Performer Series 500 CFM – Edelbrock carburetor for chevy 305


Edelbrock 1406 Performer 600 CFM Square Bore 4-Barrel Air Valve Secondary Electric Choke Carburetor

Top features

  • Size: 500 CFM
  • Choke: Manual
  • Barrel: 4
  • Material: Aluminum
  • Secondary type: Air valve
  • Flange: Square
  • Main venturi diameter: 1.19

You can’t go wrong with the Eddy. That’s what every reviewer will say.

Throttle response and acceleration smoothness

There is almost no lag time. The car moves as soon as you push the throttle. On top of that, the primary venturi is also boosted for smoother acceleration.

Installation

All the Edelbrock carburetors are very easy to install. It gets easier with an Edelbrock manifold. There is also a detailed instruction guide that helps you every step of the way.

Construction and finish

Aluminum is the best material for a carburetor, and the build quality is top-notch as well. There aren’t any gaskets below the tub-type fuel bowl and no plastic parts. This feature prevents leaks.

On top of the body, you have a ball-burnished bright barrels satin finish. This not only protects the body but also gives it a glimmering look.

Tuning and choke

You have the below three features for easy tuning of the carburetor-

  • Metering rods
  • Metering jets
  • Step-up spring

Nevertheless, the factory tuning is already as good as it can get.

Fuel economy

This carburetor is built for performance rather than mileage. However, the high-quality single inlet valve does increase its efficiency.

Pros

  • Primary venturi booster
  • Includes both timed and full vacuum
  • Low temperature
  • Rear-pivot floats
  • Easy to tune and change rods

Cons

  • Non-EGR
  • Two-piece body

2. Holley 2300 500 Cfm Universal Polished

Holley 2300 500 Cfm Universal Polished

Top feature

  • Size: 500 CFM
  • Choke: Manual
  • Barrel: 2
  • Material: Aluminum
  • Secondary type: No secondaries
  • Flange: Square
  • Main venturi diameter: 1.376

This 0-4412 model from Holley has a reputation for circle track racing. So, you are looking at one of the best two-barrel carburetors for street use.

Construction and finish

The all-metal body is made of 100% aluminum. It is as strong as it is lightweight. The body not only has a shiny finish, but it has a vibratory polish that makes it stand out under the hood. You also have down-leg boosters in the venturi for a better airdrop.

Acceleration and throttle response

If you know how to use a manual choke, there won’t be any problem with firing up the vehicle. Moreover, it has a 50cc accelerator pump. It provides the engine an extra boost of fuel for initial acceleration. And the throttle has nearly no lag time.

Installation and tuning

The ease of installation is pretty average here. But tuning the RPM is very easy. With a little know-how, you can tune the thing whenever you want.

Pros

  • Power valve blowout protection
  • Wet-flow tested
  • Precise cold start control
  • Much more economical than other models

Cons

  • No secondary

3. Edelbrock 1405 Performer 600 CFM Carburetor


Edelbrock 1405 Performer 600 CFM Square Bore 4-Barrel Air Valve Secondary Manual Choke New Carburetor

Top feature

  • Size: 600 CFM
  • Choke: Manual
  • Barrel: 4
  • Material: Aluminum
  • Secondary type: Air valve
  • Flange: Square
  • Main venturi diameter: 1.19

The main difference between this one and the 1404 performer we reviewed earlier is the CFM rating. However, the 1405 Performer is way more popular.

Installation

Edelbrock had a whole video on the installation of this carburetor. So, not that hard when you have a guideline like that. Moreover, the factory setting is perfect for your 305 Chevy.

Tuning

The manufacturer tuning is perfect for most streetcars. It uses metering rods to transition between circuits. These rods can be changed easily. You don’t have to remove or drain fuel to do that. On top of that, the carburetor can also hold its tuning for much longer.

Construction and finish

It has a two-piece body. Although it makes it compatible with both gasohol and blended fuels, I still prefer the single unit carburetor. It has tub-type bowls and rear-pivot floats. All of these make it one of the most reliable carburetors. You can get it in a satin finish which is one of my favorite.

Throttle response

The feel of the throttle is as good as Edelbrock’s reputation. There is absolutely no lagging.

Pros

  • Very popular unit
  • Versatile range of use
  • Better fuel economy
  • Best factory tuning
  • Unaffected by engine backfires

Cons

  • The erg valve might be a problem for mounting
  • Will be harder to install for new mechanics

4. Proform 67254 Street Upgrade Series 600 CFM Carburetor


Proform 67254 Street Upgrade Series 600 CFM Polished Aluminum Dual Inlet 4-Barrel Square Bore Mechanical Secondary Carburetor with Electric Choke

Top feature

  • Size: 600 CFM
  • Choke: Electric
  • Barrel: 4
  • Material: Aluminum
  • Secondary type: Mechanical
  • Flange: Square

We had a lot of experience with Proform carburetors. And we found it fairly cheap in the market. Unlike other carburetors, this American-made product is much more versatile and has an electric choke.

Throttle response and acceleration

The lag time is very less. Along with the electric choke, you also have boosters to help you with acceleration. All in all, it feels very nice under the hoot.

Tuning

The tuning is perfect for street engines like Chevrolet 305. And the mechanical secondary with four-corner idle also helps you adjust the tuning per your requirement with just changing air bleeds. Those idle feeds are also changeable. You also have changeable idle air bleeds to make temporary changes in the calibration

Installation

You just have to connect and mount the carburetor in place. Everything comes prepared from the production line. You won’t have to do any hard work. These have metering blocks with street performance calibration.

Construction and finish

The look is enough to tell you about the strength of the carburetor. The one-piece unit is a single bowl unit made with die-cast aluminum. You have a vibratory finish polished on the metal. This finish vibratory is one of the best.

Pros

  • Easy and flexible to tune
  • Fuel level windows
  • No chance of spilling
  • Accepts all conventional dual feed fuel lines
  • Accessories and parts are readily available

Cons

  • Not very popular

5. New Holley Classic Carburetor, Gold Dichromate

NEW HOLLEY CLASSIC CARBURETOR,GOLD DICHROMATE,4BBL,390 CFM,ELECTRIC CHOKE,4160,GASOLINE

Top feature

  • Size: 390 CFM
  • Choke: Electric
  • Barrel: 4
  • Material: Aluminum
  • Secondary type: Vacuum
  • Flange: Square

If you want to be the most efficient with your engine, then this is your pick. Because it is a 390 CFM carburetor, that is the closest we have to the minimum carburetor size requirement for Chevy 305, which is 375.

Construction and finish

Some sources claim that it is made of zinc. But in reality, it is mostly aluminum which is the best material for carburetors.

Holley gave the square bore small size carb a special coating of gold dichromate. This finish is much sturdier in every condition.

Installation

Installing it is easy like any other carburetor from the 100-year-old company. They included a single feed duel inlet for ease of installation. The vacuum secondary throttle response also makes it more versatile.

Tuning

You won’t need to tune it for the Chevy 305 or any other small V-8 or six cylinder engines.

Throttle and acceleration smoothness

The combination of electric choke and the straight booster makes firing up the engine very easy. And the rest of the way is smooth as well. You will not feel the difference between this carburetor from a 600 CFM carburetor.

Pros

  • Power valve blow-out protection
  • Single feed fuel inlet
  • Easy to install
  • Gasket included

Cons

  • But expensive for the size
  • Not very popular

How to Get the Best Carburetor for the Chevy 305 

Top Carburetors for Chevy 305

There are people who will just look at the CFM, brand, and price to decide their purchase, and there are also some who like to get nerdy with it. For the latter, this section will be a big help. Because we list everything, you need to look for to get a good carburetor.

We have skipped some topics because they were too obvious for even a newbie. Some of them are intake manifolds, fuel gasoline, fuel injection, throttle linkage, primary power valve, secondary air valve, etc.

Carburetor size (Cubic Feet per Minute)

The size is measured with CFM, and we have already discussed it at the beginning of the article. There we found that the required minimum size is 375 CFM for a Chevrolet 305 engine.

But most of the good quality carburetors are 600 CFM. So, one can take a 600 CFM by sacrificing a little efficiency. But we have also shown you some of the best 400 CFM and 500 CFM carburetors with all modern features.

Barrel

The Chevy 305 generates a maximum RPM of 5000. For this kind of RPM, you can use both two barrels and four barrels to maintain the air flow from the air filter. For a daily driver, 2 barrels are enough, and for a race vehicle, four barrels would be perfect.

Choke

You can go for both electric and manual choke arrangements. But if you are new, you should go for the electric choke type. This could be different for Chevy truck, Chevy & GMC.

Tuning

First of all, make sure that the factory tuning is good for your needs. Manufactures will make that clear. Then you have to see if it is easy to tune or not.

The following instruments help you to tune the car easily. See if you have that in your carburetor.

  • Metering rods
  • Metering jets
  • Step-up spring
  • Four corner idle

The metering rods should be easily changeable. And secondaries also help you to tune the carburetor and help it sustain the tuning for a long time.

Construction

Aluminum is the best candidate for a carburetor. It is both strong and lightweight. I prefer one-piece bodies. They have less chance for leakages. However, a two-piece design from a renowned brand won’t be bad. You should look for a good carb flange and fuel line as well.

Finish

There are many finish types. What you need to care for is whether it will protect against rust and corrosion. Your second thought should be about the looks and shine of the finish. Some of the popular finishes are ball burnished, satin, vibratory polish, and gold dichromate.

Fuel efficiency

Our reviews didn’t have much about fuel efficiency because getting one for a chevy 305 is hard. But we had some that are highly efficient while maintaining all other qualities.

Better vacuum secondary and specially designed boosters can help with the economy. A delayed secondary opening and lack of a secondary accelerator might also help.

Throttle response and acceleration

This is a fact that you will never find in a spec sheet. You have to read reliable reviews for a transparent deal. Less lag time and crisp throttle response is the target. Boosters and high-quality chokes help to attain this.

Frequently Asked Questions

You guys always have some questions that are not directly related to the reviews or the guide. We answer those here-

Q: What is the difference between the Chevy 305 and 350?

A: The Chevy 350 is a larger stock engine with 350 cubic inches of area, and it can handle a maximum RPM of 6000. Whereas the Chevy 305 is a smaller V8 with 305 cubic inches and a maximum RPM of 5000.

Q: Vacuum or mechanical secondaries, which is the best?

A: If you are going for a street car, we would always recommend using vacuum secondaries. They have auto transmission, and they are the most fuel-efficient. Mechanical secondaries are for racing applications.

Q: Is the biggest carburetor always better?

A: This is a very common question in a carburetor selection. Every engine has its maximum breathing ability. A carburetor is using its potential to that amount. Anything more is a waste of power.

Q: Is a 750 CFM carburetor too big for the Chevy 305?

A: Yes, it is too big for it.

Q: Will a new carb make the Chevy 305 faster?

A: If the old one is too old or damaged, a new carb will always make the engine faster.

Final Thoughts

We already showed you the best carburetor for 305 Chevy. But hey, we know some of you guys like to play with your ride. And those guys know that some of our recommendations were a bit out of the ordinary. But we know you will like it.

BTW, you can also read our another article on the 350 Chevy engine Carburetor here!

Best of luck!

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