Chevrolet's 305 Engine - VehicleHistory (2023)

Braden Carlson

Apr 27, 2021

The Chevy 305 is a small displacement V8 built with efficiency in mind. Although it isn’t that powerful, is it a diamond in the rough?

Chevrolet's 305 Engine - VehicleHistory (1)

When it comes to iconic engines throughout history, the Chevrolet Small Block V8 reigns king. It’s an engine that will come up at any discussion, whether the topic is efficiency, horsepower potential, or reliability.

However, most people immediately associate the term “small block Chevy V8” with the iconic Chevy 350 found in just about every GM vehicle that was produced between its introduction in 1967 until its final breath as the Vortec 5700 in 2002.

However, the 350 is not our topic of discussion. Instead, we’re going to take a look at the Chevy 305. Born as a solution to the gas crisis brought on by the Organization of Petroleum Exporting Countries (OPEC) Oil Embargo of the 1970s.

Gas prices were at an all-time high, and automakers were pushed to create more efficient vehicles in a time where there was an active battle between America’s biggest car manufacturers to create the most ferocious and powerful muscle car.

While the immediate solution that comes to mind for creating a more efficient engine may not be a slightly smaller V8, the 305 actually did quite well at what it was designed to do. Though, power and performance are not exactly part of the 305 notoriety.

We’re going to take you through the history of the Chevy 305 V8 and give you the specs and what models you’ll find it in. While many people who own 305-powered cars choose to yank them out and put something with a bit more power in them, perhaps a 305 powerplant isn’t all that bad. If you’re looking for the classic V8 and muscle car sound without killing your wallet at the gas pump, the 305 may be exactly what you need.

Chevrolet's 305 Engine - VehicleHistory (2)

History of the Chevy 305 V8

The Chevy 305 was first introduced in 1976. While the OPEC Oil Embargo sent the country into a gasoline crisis, this was not the only driving factor behind the production of the Chevy 305 V8.

Additionally, the U.S. Corporate Average Fuel Economy (CAFE) standards were getting more stringent, and nationwide emissions requirements were getting stricter.

While we are pretty used to very high horsepower engines that still get decent fuel economy today, the limited technology of the mid to late-’70s didn’t allow them to have their cake and eat it too as we can today.

As a result, the 305 and all V8s of the time make some pretty disappointing power figures and would continue to do so on into the early-’90s.

Given that the 305 is built on the architecture of the generation one Chevrolet Smallblock V8, many of the parts are shared between the 305, 350, and other small-block V8s. Thanks to this shared platform, the 305 was inexpensive to produce and made for a reasonable solution to needing a more efficient engine without designing one from scratch.

General Motors then put the 305 in everything from Chevy trucks and SUVs like the C10, Blazer, and work vans to cars like the Chevy Camaro and Nova, as well as many other GM vehicles like the Pontiac Firebird and Grand Prix as well as the GMC lineup of trucks and vans.

All 305 engines throughout the years share bore and stroke specs of 3.736 × 3.48 inches. Beyond that, there are a handful of variants that feature different horsepower, torque, and even fuel management. Initially, the 305 was carbureted.

However, it would go on to use Chevrolet’s Crossfire Electronic Fuel Injection system and, in later years, move on to Tuned Port Injection.

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Let’s take a look at the changes to the Chevy 305 and its engine codes over the years.

Chevrolet's 305 Engine - VehicleHistory (3)

Chevy 305 Engine Variants

From 1976 to 1980, the 305 came in the form of the LG3 engine. It features a two-barrel carburetor with an 8.5 compression ratio. It makes a maximum of 160 horsepower and 250 lb.-ft. of torque. Though, in the late 70s, Camaros and Novas only saw 145 horsepower out of the 305.

Next in line is the LG4. It is virtually identical to the LG3. However, it comes with a four-barrel carburetor instead of a two-barrel. While this didn’t make for a massive leap in power, it was good for a step up to a maximum output of 170 horsepower and maintaining the peak torque figure of 250 lb.-ft. The LG4 was produced from 1980 to 1987.

Overlapping the years of the LG4 from 1983 to 1986 was the higher output variant, the L69. Though it maintains the four-barrel carburetor, compression of the L69 is bumped to 9.5 to 1. The result is the maximum power outputs of the L69 are 190 horsepower and 240 lb.-ft. of torque.

From 1981 to 1986, Chevy produced another four-barrel variant of the 305, the LE9. It also has an increased compression ratio of 9.5 to 1. However, its maximum power figures are 165 horsepower and 250 lb.-ft. of torque.

The model year 1985, The Camaro Z28 had a special variant of the 305 that was only available with an automatic transmission known as the LB9. It made 215 horsepower and 275 lb.-ft. of torque. 1988 through 1992 Camaros received a variant of the LB9 305, ranging from 220 and 230 horsepower depending on the year.

Truck variants of the 305 lasted until 2003 in the form of the L30, known as the Vortec 5000. This engine can be found in Chevy and GMC C/K series trucks and GMC Savana work vans.

Chevrolet's 305 Engine - VehicleHistory (4)

How Fuel-efficient is the Chevy 305?

Like we mentioned before, the idea of keeping a V8 as a fuel economy solution doesn’t immediately strike as the best solution. Alternatively, Chevrolet offered the Camaro with a V6 and even the Iron Duke inline four-cylinder. Though, to eliminate the V8 entirely from the Camaro would have been a marketing disaster.

However, the 305 has EPA fuel economy ratings that will surprise you. EPA ratings were not available until 1984. Let’s take a look at the EPA ratings of the Chevy Camaro with the 305 V8, as it continued to use this engine until 1992.

A 1984 Chevy Camaro with the 305 V8 mated to an automatic transmission has an EPA rating of 15 mpg city and 21 mpg highway for a combined rating of 17 mpg. Likely, many people researching the economy of an old Muscle car will be dumbfounded to see a rating over 20 mpg. We certainly were.

Moving up to the 1988 Camaro, also equipped with a 305 and four-speed automatic, we see the ratings increase to 15 mpg city and a whopping 24 mpg highway for a combined rating of 18 mpg. This rating remains the same through the 1991 model year.

In the 305’s final year under the hood under a Camaro, 1992, you’ll find an EPA rating of 15 mpg city and 23 mpg highway.

These numbers drop a tad when equipped with a manual transmission.

However, the EPA numbers are actually quite surprising. In 1990, a V8-powered car with over 200 horsepower that manages to get over 20 mpg highway was nothing short of astonishing.

Chevrolet's 305 Engine - VehicleHistory (5)

(Video) Best Engines of All Time: The Chevrolet Small Block V8 (262/265/283/302/305/307/327/350/400)

Chevy 305 Potential and Reliability

While the Chevy 305 did not come with substantial power by today’s standards, it is still a small block of Chevy V8. Given that it shares platforms with the hot-rodder’s engine of choice, the 350, there is a slew of aftermarket parts available.

Simple upgrades like a better flowing intake manifold, a better carburetor, and a camshaft upgrade can be performed with basic hand tools and can increase power output by over 100 horsepower.

Additionally, a plethora of exhaust manifolds, electronic ignition, and many other performance upgrades are plentiful.

One thing that needs not be questioned is the reliability of the Chevy 305. Old engines will have plenty of issues, like failing gaskets, oil leaks, and worn-out hoses.

However, there is nothing exclusively problematic with the Chevy 305. Much like the 350, it carries notoriety for being able to get you from A to B under just about any circumstances.

Obviously, when shopping for an older car, it is important to understand that you will likely have to work on it or maintain it more often than a new car.

However, knowing a car’s accident and maintenance history is extremely important in picking the right car. A great place to start is with our free VIN lookup tool that shows the history of recall repairs, accidents, and sales reports. Additionally, buying a well-maintained vehicle with service records is imperative if you are searching for a reliable driver.

In short, the 305 is not a bad option when considering power capabilities and reliability. Like with most cars and their engines, if you treat them right, they will treat you right.

Should You Buy a 305 Vehicle?

You’ll find that many old-school Chevy enthusiasts choose to steer clear of the 305 due to its notorious lack of power. Many original 305 vehicles that get restored receive a crate engine 350 or an LS swap.

However, well-maintained all-original cars are continuing to climb in value. If you come across one relatively cheap, you may be acquiring an appreciating asset.

Whether you’re considering the potential profit or not, the Chevy 305 is a very reliable V8 that gets amazing fuel economy for its era. It may not be the most powerful option there ever was, but owners can fix that with aftermarket modifications if that’s what you’re after.

If you want a classic Chevy V8 that will reliably fire up and take on a nice cruise or a simple, reliable truck that doesn’t need to move the whole world, the Chevy 305 is likely to be everything you need.

Photos: Chevrolet

Frequently Asked Questions

Apr 17, 2022

Is the Chevy 305 a good engine?

The Chevy 305 engine is a perfectly good engine that works great in a lot of road-going cars and they can be tuned up to provide great power output. They are very similar in size to the Ford 5.0L V8, yet they do not get the same respect because Chevrolet has made larger engines like the 350 and 454 that are more popular.

The main downside to the 305 is of course the size, it is a smaller V8 compared to a lot of other options. The bore size is the ultimate limit for this engine. Many 305s are thrown out when they get worn out and replaced with larger 350s since they share a lot of the same components.

The 305 is an underappreciated engine and I think that nice examples of them in the future will become valuable as people start to care more about originality instead of power. Since many classic cars came stock with the 305 it is nice to see them in the vehicles.

Are 305 and 350 blocks the same?

The blocks for the Chevy 305 and the Chevy 350 are the same. They have the same mounting location and size, the main difference between the two engines is the bore size and piston size. The 350 gets a lot more attention than a 305 even though they are very similar to each other in terms of architecture.

It is possible to put a 350 head onto a 305 to help improve its output and performance by allowing more air to flow through the head. They were produced from 1976 until 2002 whereas the 350 is older and was made from 1967 through 2003. The 305 was introduced when cars started to become lighter to give a similar performance with a lighter chassis that did not need as much power.

If you have a car with a blown 350 or 305 in it then you can easily swap the motors. They tend to work well with the same transmissions as well so it should be a fast swap.

What is the horsepower of a 305 Chevy engine?

The Chevrolet 305 was not a very powerful engine when it was produced, depending on the car that it came in they only made about 220 to 230 horsepower. This was fine though for a lot of the lighter cars that Chevrolet was making in the late 70s, 80s, and early 90s.

The 305 can be built to make about 450 horsepower though if you add things like a supercharger and larger carburetors to it. They are still a small block V8 that is made by Chevy and there are plenty of parts on the market for them.

The 305 may not be as powerful or popular as the 350 or the 454 but they can still be built to make a good amount of power. They also look great in vintage muscle cars where they are the original engine that came with the car. Going with a 305 is a great way to keep that classic feel.

(Video) 350 and 305 Chevy what's The Difference

Owner Reviews

messageEdit Write a Review

Ernie Sanders on August 18, 2022

1997 Truck 305

283000 miles still running.what would give me more horsepower.It was interesting about the 305 in the cars,but I thought the 307 ,327 and 283 was better

(Video) Worst Engines of All Time: 1982-84 GM/Chevrolet 305/350 V8 Cross-Fire Injection System

Rick Flynn on October 9, 2022

Thanks for the info!

Great detail and well written, Thanks! :-)

RAMS on April 26, 2022



Braden Carlson

An automotive journalist for over six years, Braden Carlson has contributed to a variety of auto websites, including Team Speed and LS1Tech. When he’s not writing or under one of his project cars, you’ll often find him producing video and photography for his "Cursed Forever" YouTube channel.

(Video) The Truth About The Small Block Chevy 305
  • Articles
  • Chevrolet’s 305 Engine


What years did Chevy make 305 engines? ›

They were produced from 1976 until 2002 whereas the 350 is older and was made from 1967 through 2003. The 305 was introduced when cars started to become lighter to give a similar performance with a lighter chassis that did not need as much power.

What was the last year for the 305 engine? ›

The 305 was GMC's standard pickup truck and Suburban engine from 1960 to 1974. The 305A was standard in 1000–3500 series trucks in 1960-1961 and was dropped in 1962. The 305D was an option in the 1000–3500 series in 1961 and became standard in 1962, replacing the 305A.

How much horsepower can you get out of a Chevy 305? ›

Produced from 1976 to 1998, the much-maligned 305 was never intended to be a performance engine like some other small-blocks. Regardless, it was pushed into that role with the third-generation Camaro, where its output would top out at 210 horsepower with a Tuned Port Injection system.

Is a 305 better than a 350? ›

While the 305 does better at fuel mileage because of its smaller displacement, ports, and valves, the 350 is excellent at power. All thanks to its larger ports, valves, and displacement. So, even if you're getting better fuel efficiency with a 305, it does not make up for its deficiency.

What cars came with a 305? ›

The strong 305 Chevy engine showed up in the Camaro Z28, Trans Am, GTA, Firebird, Corvette, Caprice, IROC-Z and was standard equipment for the Monte Carlo Super Sport. It was a very versatile motor and also showed up in boat engines produced by Mercury Marine until late into 2014.

What is the difference between a 302 and 305? ›

The 302 Ford combined a 4.0-inch bore with a 3.0-inch stroke. This compares to a 3.736-inch bore and longer 3.48-inch stroke for the 305. The 305 Chevy is often chastised for its small bore, but under the operating conditions the stock engines were intended to run, the bigger bore is of little benefit.

What is the biggest small block Chevy? ›

The LS7 is the largest factory-installed small-block Chevy V-8 ever, displacing 427.8 cubic inches or just over 7.0 liters. It featured the same bore as the 1970s 400-cubic-inch engine of 4.125 inches (104.8 mm), but unlike the 400, the LS7 got a full 4.00-inch (102 mm) stroke crankshaft.

How much horsepower can you get out of a small block Chevy 305? ›

You can make 450 hp, but this will require a much-longer-duration camshaft to make torque at higher engine speeds-around 6,500 rpm.

What is the most power out of a 305? ›

A solid 305 with some proven upgrades can deliver 250 horsepower, wicking things up to 300 horsepower and 300 lb-ft of torque is achievable and power adders can open the window to even bigger numbers.

Can a Chevy 305 be stroked? ›

The 305 uses a tiny 3.736-inch bore and the same 3.48-inch stroke as the 350ci motor. While it's relatively easy to drop a 3.75-inch stroke crank in a 305 block to create a 0.030-over stroker that displaces 334 inches, it's just not a great performance decision for several reasons.

How much HP does a 305 V8 have? ›

Run in this manner, the TPI LB9 305 produced peak numbers of 267 hp at 4,700 rpm and 333 lb. -ft. of torque at 3,700 rpm. It should be obvious from these numbers (especially the peak engine speeds), that GM designed the long-runner, tune-port motors for low-speed torque.

How much does a 305 weigh? ›

The 305 weighs in around 11,700 lbs. making it a powerful piece of machinery with enough muscle to do some serious digging.

What is the difference between a 305 and 307 Chevy? ›

The most major difference is the bore. The earlier 307 Chevy is effectively a stroked version of the 3.875" bore 283, with the 3.000" crank replaced by the 327's 3.250" stroke crank. The later 305 is effectively a de-bored 350, sharing its 3.480" stroke, but has a tiny 3.736" bore.

Is the Chevy 305 a big block? ›

This seems odd since it's a Chevy small-block under the skin, but in the performance world, just as in nature, bigger is almost always seen as better. In reality, 305 Chevys (including our carbureted LG4 version) make great street engines and can be the basis for impressive performance machines.

What year did Chevy put the Vortec 350? ›

The run on the Vortec 350 engine was relatively short: It hit the market in 1996 and was replaced with GM's new-generation engine line by 1999.

What car has a 305 small block? ›

Produced until 1998, the 305 found its way into a wide variety of GM vehicles including the Camaro, Firebird, and Chevrolet/GMC pickup, just to name a few. Dart's Little M 305 block is a popular base for RaceSaver Chevy 305 engines.

Did Corvette ever have a 305? ›

smallblock in the 1980 Corvette be replaced with a wholly inadequate 305 V8, putting out 180 hp of pure shame. On top of that, the "California" Corvette sucked its pitiful rivulet of horsepower through the straw of a torque-sapping three-speed automatic transmission.

Did Buick make a 305 engine? ›

305. The 305 cu in (5.0 L) was a Chevrolet V8 engine shared with Buick: 1978–1987 Buick Regal. 1975–1979 Buick Skylark.

Are HP 303 and 305 the same? ›

HP has recently launched a new ink cartridge called the HP 305. It will not work with HP 304, HP 303, HP 302, or HP 301 ink cartridges so please make sure you only buy the cartridges that are already clearly marked in your printer.

Did Chevy ever make a 302? ›

302. In 1966, General Motors designed a special 302 cu in (4.9 L) engine for the production Z/28 Camaro in order for it to meet the Sports Car Club of America (SCCA) Trans-Am Series road racing rules limiting engine displacement to 305 cu in (5.0 L) from 1967 to 1969.

What is a Chevy 305 engine? ›

Actually, the 305 is a small-bore, long stroke engine created when General Motors officials decided back in the '80s to phase out the V8 in favor of the V6. Then, the plan was for the 305 to be the biggest V8 you could purchase. The problem was that the only V6 making decent power was the turbocharged Buick V6.

What is the strongest Chevy engine? ›

Chevrolet Performance ZZ632/1000

What is the best SBC ever made? ›

The potent 327 L84 held the title as the most powerful production small block Chevy engine for nearly 30 years! That's an impressive feat for an engine developed way back in 1964, especially considering it gave up precious cubic inches to the larger small blocks developed later on.

What is the best Chevy engine for hot rod? ›

Ubiquitous and affordable, the original small block Chevrolet V8 is the most popular high performance and hot rod engine in the world.

What is the fastest Chevy small block? ›

It first appeared in 2010 and by 2012 Copeland had hit a staggering top speed of the meet at 380 mph with an official two-way record at 364.051 mph, a record that still stands.

What size carb do I need for a 305? ›

➥➥ Best carburetor for Chevy 305: Your two best choices here are either the classic Edelbrock 1406 600 CFM or for 305 V8, I'd recommend you a Holley Speed Demon 625 CFM. Optimal CFM range: 550-650.

Is 305 hp good? ›

Right between 200 and 300 horsepower is the sweet spot for many drivers. Be cautious with models that approach 300 horsepower, unless the vehicle is a heavy truck or another large model.

Can you supercharge a 305 small block? ›

Capable of supporting over 700 hp on the right application, the TorqStorm supercharger was perfectly sized for our modified 305. The kit supplied by TorqStorm included the supercharger (with pulley), mounting bracket, and crank pulley assembly (including the hub-centric spacer).

Is a 305 and 350 crank the same? ›

305-350 cast cranks were the same casting number and the only difference was the factory balancing.

What engine puts out the most power? ›

Bugatti Chiron (8.0 litre W16)

The Bugatti Chiron boasts a four turbo, 8.0-litre W16 engine, which is undoubtedly the fastest in the industry. This engine can produce 187.5 horsepower per litre, totalling 1,479 HP. In addition to that, this car also has an incredible torque of 1,600 Nm at 2,000 to 6,000 rpm.

What is the difference between a stroker engine and a normal engine? ›

As its name implies, a stroker is where we increase engine displacement by increasing piston stroke. When we increase stroke, we take the piston deeper in the cylinder bore, which increases displacement. The longer the stroke, the greater the fuel/air charge.

What year is the best Chevy 305 engine? ›

What year is the best Chevrolet 305 engine? The simple answer to this question is that it depends. If you're looking for high horsepower, look to a later fuel-injected model in the late 1980s or early 1990s. If you'd prefer a carburetted model, a late 1970s or early 1980s model will do well.

What is the most reliable Chevy truck engine? ›

What is the Best Chevy Silverado Engine? The new 6.2-liter EcoTec3 V8 option is the best engine for a Chevy Silverado, that is if you're focused on horsepower and torque. The Chevy Silverado lineup offers various engine options, though, that all provide incredible performance and capability.

Did Chevy make a 305 Vortec? ›

After 1996, GM installed the Chevy 305 in small Chevy and GMC trucks and SUVs and renamed the Vortec 5000. In the 21st century, the Vortec was placed in vans and some commercial automobiles until 2003. Today, it is one of the more widely available engines for remodeling projects.

How much horsepower does a 1980 305 have? ›

The hot-dog 305 engine in the mid 1980s was the L69 carbureted engine used in early third-gen Camaros. While considered a hotter engine than its LG4 counterpart, it was only rated at 190 hp.

Did Ford make a 305 engine? ›

But what it did have was a 305 horsepower 3.7-liter V6 that was an absolute gem of an engine. It made 280 pound-feet of torque at 4,250 RPM and it was mated to a six-speed manual transmission. A six speed automatic transmission is also available.


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