Within the classic car community, debates between enthusiasts about big block vs. small block Chevy engines can get intense. Many drivers have strong opinions over which one is the “better” engine, but each engine type presents its own advantages and holds a unique place in the history of muscle car manufacturing.

Block Engine Basics

Nearly all of today’s engines belong to what is known as the “monobloc” family, which was introduced by Cadillac with the 1936 Monobloc V8. However, when referring to block engines, the term applies specifically to the V8 pushrod engines designed after 1955. These engines, alternatively referred to as overhead valve engines, are a staple of classic muscle cars. They’re highly desired by car enthusiasts due to a few key features:

• Ease of maintenance: Pushrod engines are significantly easier to work on than overhead cam engines, which can simplify maintenance.
• Weight distribution: The engine and its components make up a significant part of a vehicle’s weight, but block engines sit lower in the car, giving the car a lower center of gravity. Many drivers like this for the sake of performance and safety.
• Drive feel: Block engines tend to have an easier time getting low-end torque, which can provide a specific drive feel that some drivers prefer.

Big Block vs. Small Block Engines: What’s the Difference?

Block engines are referred to as big block or small block. These common names focus on their differences in size, but these engines also differ in function. To understand these differences, you first need to understand the metrics that differ between the two engine types.

1. Displacement

Displacement is a measurement of the volume of an engine’s pistons, often referred to in cubic inches or liters. As an example, 400 cubic inches is equivalent to 6.6L. In older cars, displacement is most commonly described in cubic inches as this was the standard unit at the time of manufacture.

This measurement is often used to express how powerful the engine is, but it’s important to remember that displacement doesn’t always relate directly to power. Larger displacement values indicate that more air and fuel can be taken in — this usually correlates to more power, although the specific architecture of the engine also plays a factor.

2. Bore and Stroke

While displacement is usually considered the primary delineation between small and big block engines, displacement volume depends on two other engine measurements that play a significant factor in the big vs. small block determination:

• Bore: Bore size refers to the diameter of an engine’s cylinders. Big bores result in improved breathing, which increases the amount of power produced by the engine. Smaller bores create more pressure and torque, though they tend to have greater limits on red line numbers.
• Stroke: The stroke is the distance a piston has to travel up and down in the cylinder of an engine. Pistons with shorter strokes do not have to travel as far each cycle, so they can produce more strokes in the same amount of time as an engine with longer strokes. This increases rpm, which increases the engine’s maximum power. Longer strokes lose less energy to heat, resulting in greater energy efficiency.

3. Size, Shape and Weight

Though size and shape are not primary functional factors for Chevy big block vs. small block engines, they are important to know and consider. When displacement is the same between two engines, the features that determine whether an engine is a big block or small block often come down to physical proportions, engine “families” and the shape and placement of the valves.

Chevy Big Block Engines

Big block engines are beloved among enthusiasts for their power and typically come in 2-bolt and 4-bolt mains. This engine type is characterized by the following metrics:

• Displacement: Big block engines tend to have displacements of 400 cubic inches or more. There are exceptions to this rule, such as the Chevy 396 engine which is referred to as a big block engine due to its architecture.
• Bore and stroke: These engines tend to have larger strokes, smaller bores and bigger valves and ports than small block engines. This increases both efficiency and displacement, which is necessary for larger vehicles that need more power. As a result, big block engines can perform consistently in higher-demand situations.
• Size and shape: Big block engines are physically larger than small block engines. They are more square in shape, with an overall  “Y” shape due to the additional space needed. The cylinders are placed further away from one another to maximize airflow — big block engines are sometimes referred to as “porcupines” because of their canted valve setups. This valve setup is used to achieve increased spacing between valves, causing it to resemble the quills on a porcupine.
• Weight: Because of their increased size, big block engines also carry more weight. This extra weight adds pounds to the front axle that can negatively impact handling and acceleration.

The History of Big Block Engines

Big block engines, also known as “Rats” or “Turbo-Jet” motors, were introduced by Chevrolet in 1958 with the Mark 1 or W series. This engine series was designed to provide the extra power needed for the heavy passenger cars and trucks developed after World War II. These motors boasted 348 to 409 to 427 cubic inches of displacement and provided over 430 horsepower, which gave these heavier cars the power and torque they needed. They also had a design that featured offset valves and scalloped rocker covers, which became staple features of classic big block engines.

Chevrolet had a corner on big block engine production through the early to mid-60s, producing the W series of big block engines from 1958 to 1965. In that time, they also developed Mark II, Mark III and Mark IV big block engines, the latter of which was featured in the flagship Corvette model and continued through 1974. The big block engines became so beloved that many Jeep owners even elected to swap out their engines with the Chevy big blocks.

In the late 60s, Ford and Chrysler followed the trend by producing their own big block engines. The big block engine did see a significant slowdown starting in the 70s, however, as fuel prices increased and emission control became more of a concern in light of the growing environmentalist movements.

Big Block Engines Today

The last of the true Chevy big block engines was the Generation VII Vortec 8100, which was produced from 2001 to 2009. With modern materials allowing engines to produce more power with less materials, many experts agree that today’s “big block” engines are simply small block engines with large displacements.

While the big block engine may not be in production anymore, the big block is still well-loved within the classic car community. Many car enthusiasts love the way big block engines sound and feel, so they choose to install them for restorations or custom builds.

Chevy Small Block Engines

Small block engines, also referred to as “mouse motors,” are the small but mighty iteration of the block engine. Small block engines are characterized by the following metrics:

• Displacement: Older small block engines typically have displacements of less than 400 cubic inches. More recent iterations, however, have achieved larger displacements due to improved airflow. By creating additional airflow, these smaller engines can achieve similar displacements as big block engines.
• Bore and stroke: Small block engines have larger bores and smaller strokes. The shorter strokes of small block engines tend to result in less displacement, but make quicker revving possible.

• Size and shape: Small block engines are smaller than big block engines. These engines tend to have a more characteristic “V” shape associated with V8 engines.
• Weight: While small block engines may not produce as much power as big blocks, they make up for it in being lighter-weight. The light-weight nature of small block engines puts less weight on the front axle, improving handling and acceleration.

The History of Small Block Engines

The small block was the V8 that started it all, predating the big block by decades. The first small block was the Chevrolet Series D V8 engine offered from 1917 to 1919. While historically important, this short-lived series didn’t make a huge impact and was quickly outshined by the standard six-cylinder Chevrolet engines used in passenger cars through the mid-50s.

Unlike with the big block engines, Chevrolet actually fell in with the small block V8 trend after other automobile companies had already produced their own models. The Ford Flathead V8 started the trend in the 1920s, quickly becoming popular with hot rodders for the engine’s power potential, and then converting to an overhead valve Y-Block configuration in the mid 1950s. Cadillac, Oldsmobile and Chrysler followed suit with the OHV V8, Rocket and HEMI, respectively.

While Chevy was late to the game, they made sure to produce an engine that would beat the competition and pave the way for small-block engines. In 1955, the 265-cubic-inch small block, called the “Turbo-Fire,” debuted in the Corvette and Belair models, delivering two times as much horsepower in half the weight of the Ford Flathead. This small block V8 cut the 0-60 mph time of the Corvette by 1.5 seconds and featured a 4.4-inch bore spacing that became a design staple of small-block engines. The small but powerful engine quickly earned the nickname of “Mighty Mouse,” which led to small block motors being called “mouse motors.”

The popularity of the Turbo-Fire model exploded because of its size, durability and power, becoming the engine of choice for hot rods, muscle cars and drag racing. GM quickly developed a lineup of 283, 327, 350 and even 400-cubic-inch engines, changing the bore diameter and stroke length of the design for more capacity.

Small Block Engines Today: LS1 Engines and Beyond

The Chevy 350 cubic inch small block was the GM standard until it was discontinued in 2003. While the old small block models are discontinued, modern small block engines are still being produced — GM produced its 100-millionth small block engine in 2011, and many small block engines are built in Mexico as crate engines for restoration and custom-build enthusiasts.

While Chevy still uses small block engines in many of their vehicles, they don’t look or function the same as they used to. GM discontinued the traditional small block design with the third generation of small block engines, starting with the LS1 in 1997. This all-aluminum model featured smaller bores and longer strokes than in previous generations, producing 346 cubic inches of displacement and 345 horsepower in the Corvette. The Chevy LS1 engine was produced between the 1997 and 2004 model years and was featured in the Corvette, Camaro, Firebird and GTO models.

Following the success of the LS1 engine model, GM continued the LS series and developed new generations of the small block engine model. Chevrolet is currently manufacturing the fifth generation of small block V8 engines with the Gen V LT1, which was introduced for the 2014 Corvette Stingray. At this point, Chevrolet has phased out big block engines entirely for the more efficient small block models, and you can find these models in everything from Corvettes to trucks.

Quality Restoration Parts

When it comes down to it, the determination of what a big block engine is versus what a small block engine is comes down to the size of the engine and when it was manufactured. Big block engines are larger in size and weigh more, but they produce more consistent power and torque to overcome the weight. Small block engines are smaller for better acceleration and handling, but more recently built models can be just as powerful as big block engines. Whether one is better than the other comes down to the user and what they are looking for.

If restoration is your goal, Raybuck Auto Body Parts can help with your interior and exterior details. We carry everything necessary for restoring classic Chevy and GMC cars dating back to 1939. With 35 years in the industry, a massive catalog of products and competitive pricing, we are restoration enthusiasts’ online source for quality New Old Stock alternatives. Regardless of whether you’re getting a car show-ready, restoring a classic car or bringing your project to mint condition, Raybuck can help with repair panels, replacement parts and hands-on restoration expertise.

If you’re interested in Chevy restoration parts, use Raybuck’s advanced website search options to search for parts by year, make and model and checkout securely online. If you want to learn more about our parts or receive expert advice to inform your purchase, get in touch with Raybuck’s team today.

The Pontiac Firebird was one of the most iconic muscle cars of the late 1960s through the early 2000s, rivaling other famous models like the Ford Mustang and Chevrolet Camaro. The Firebird went through quite an evolution in its nearly 40-year history, with its engine’s capabilities changing and its body continuously getting reworked and improved. The vehicle didn’t just make an impact on muscle and pony car enthusiasts — it also entered the mainstream pop-culture world, appearing in multiple TV shows and movies.

In this guide, we’ll dive deep into Firebird history so you can learn more about the iconic muscle car’s development and get some of the most interesting facts about the pony car’s many years in production.

Quick Links:

• First Generation of Firebirds
• Second Generation of Firebirds
• Third Generation of Firebirds
• Fourth Generation of Firebirds
• Fun Facts

The Pontiac Firebird vs. Trans Am

The Pontiac Firebird and Pontiac Trans Am made a significant mark on the auto industry. Both vehicles were iconic, with a few Trans Ams even making it into movies and TV shows. To understand the mark both the Firebird and Trans Am had on the industry, you should know how they’re different.

What’s the Difference Between the Pontiac Firebird and the Trans Am?

Are the Firebird and Trans Am the same? The truthful answer is yes and no. While all Trans Ams are Pontiac Firebirds, not all Firebirds are Trans Ams. This is due to Trans Ams being a type of Pontiac Firebird started as a specialty package in 1969.

The Trans Am essentially took the Firebird’s performance to the next level. Compared to their Firebird counterparts, Trans Ams offered upgraded horsepower, handling and suspension. Through all four generations, you could purchase a Trans Am instead of the base Firebird if you wanted to take your performance to another level.

History of the Pontiac Firebird

The Pontiac Firebird lasted for four generations, with models in production from 1967 through 2002. General Motors designed the vehicle to be a pony car that could take on the Mercury Cougar and the Ford Mustang. The name came from previous concept cars and the General Motors Firebird prototype cars from the 1950s. These Pontiac Firebirds would go on to be some of the most iconic muscle cars to ever hit the market.

First Generation of Firebirds

The first generation of Firebirds was relatively short-lived, lasting from 1967 to 1969, but this generation made a mark, setting up many more generations.

The first Pontiac Firebird models came in either two-door coupe or two-door convertible options. Though firebirds were built on the Chevrolet Camaro’s platform, they were constructed using different parts, helping to separate the new Firebirds from the Camaro. Unlike the Camaros, the Firebirds featured body-integrated front bumpers and different engines.

These first Firebirds came with a 3.8 L6 engine that offered 220 horsepower. Buyers who wanted to get more performances out of their new car could purchase a Firebird with an upgraded 6.6-liter V8 engine that packed 340 horsepower.

Buyers who chose the L6 engine could also expect to hit a top speed of 114 mph and go 0-60 in just over 10 seconds. Additionally, the engine featured 240 lb.-ft. of torque. Selecting the L6 version of the Firebird also meant you also got 4-speed manual gearbox with Safe-T-Track – Pontiac’s version of posi-traction – as optional equipment.

With the V8 version, buyers received a 3-speed automatic instead of a manual transmission with the same optional equipment offering. Alongside its impressive horsepower, it also featured 430 lb.-ft. of torque. This generation of the Firebird also saw the arrival of the Firebird Trans Am in 1969.

The inaugural Firebird Trans Am released in 1969 got off to a slow start. It was offered as a Trans Am Performance and Appearance Package and cost $725. It had very little media hype around it and no advertising. The name for the car was inspired by the Trans American racing series to allude to the car’s performance.

The base engine that came with the Trans Am was a 400-cid V-8 engine that had a brake horsepower of 335. Other performance advantages Trans Ams gave buyers included a one-inch front stabilizer bar, a heavy-duty suspension system, variable-ratio power steering and seven-inch-wide rims featuring Polyglas F70xl4s.

The 1969 Trans Ams came with a unique look as well. They all were painted Polar White and had blue racing stripes across the top of the vehicle’s hood and trunk. The cars also had a 60-inch airfoil across the rear deck. The rear-facing hood scoops were made out of fiberglass and were constructed to help vent the car’s engine bay. Finally, the car had functional air inlets included that were controllable by the driver, who could open or close them.

Though the initial Trans Am didn’t come out to much fanfare, it became one of the most popular options for drivers looking for a high-performing Firebird.

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Second Generation of Firebirds

Following this first round of Firebirds, the second generation of the vehicle hit the scene in 1970 and ran until 1981. The new generation of Pontiac Firebirds brought with them a new look for the vehicle.

One major appearance change was the front of the Firebird getting two stylish air intakes added to it. Additionally, the Firebird switched from four circular headlights to two large headlights, which changed the look of the car’s front significantly. Convertible lovers were in for a harsh reality during this generation, as a convertible model didn’t carry over from the fourth generation.

This generation gave Firebird buyers even more options that enhanced performance. The 1970 model saw four different engines and three transmissions. Notably, you could get a three or four-speed manual or a two or three-speed automatic, making the car suitable for different types of drivers.

The second generation gave users only an average amount of power, but Pontiac quickly put out a stronger 6.6-liter Ram Air IV motor. In 1971, buyers had access to a 7.5-liter engine. Though it looked like the sky was the limit for the Firebird’s power, the car got hit with new regulations and high fuel prices, diminishing its power potential.

By 1974, the Pontiac’s weight had increased significantly due to new five mph bumper requirements and other safety features. The change to unleaded fuel at the time caused a reduction in compression ratios which dramatically decreased the car’s power output. Regulations relating to limiting carbon monoxide and hydrocarbon also made it so ignition timing took longer, and cams weren’t as aggressive.

By the end of the generation, the Pontiac Firebird’s top power had gone down significantly. The most powerful V8 engine you could get only put out 200 horsepower, a far cry from the early Ram Air engines. One notable featured that came later in the generation was a Firebird decal that gave the car an extra flair.

The Trans Ams of this period saw a decrease in power as well. They started with a 6.6L V8 engine and progressed to a 7.5 L V8 engine, but by the end of their run were down to their top engine being a 4.9 L Pontiac turbo V8. Compared to the standard Firebirds of the period, the Trans Am boasted a much-improved suspension system.

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Third Generation of Firebirds

The third generation of Firebirds would be a strong one, with new model years releasing from 1982 to 1992. While the past generation had been hampered by changing regulations and a need to add new features, the third generation of Firebird was better prepared to handle the new regulations on their industry.

Instead of staying with the heavy design of the Firebird from the past generation, Pontiac constructed the car in a new form that featured a more aerodynamic design. This design was built for efficiency, with a much lighter weight and much easier handling. The company dropped hundreds of pounds off of the previous generation and made the car much smaller. With the loss of weight, they crafted a wedge-like appearance for the car’s body.

The vehicle was a 3-door hatchback coupe that offered four different engine choices at the beginning, making it more customizable to the desires of the buyer. These engine options ranged in their ability, with 90 to 238 horsepower options available, depending on the engine. The final 1982 model arrived with a four or five-speed manual transmission or a four-speed automatic.

Pontiac employees also developed a new chassis that made the vehicle more aerodynamic, working on the car’s development in a wind tunnel to ensure they could achieve the aerodynamic design they wanted. This creation process resulted in windshields that sloped at 62 degrees.

The car also saw a change to the headlights, as they now were hidden underneath panels.  Near the end of the generation, the 1991 Firebird came with a convertible option, bringing back a favorite feature of some.

The Trans Am of this period came with a new appearance meant to give it a more high-tech look. To make their high-tech appearance really work, designers used a matte gray finish on its unique features, like the dual mirrors, turbo wheel covers, grilles, door handles, functional air exhaust and a wing. Like past Trans Ams, this version of the Firebird also offered a boost to power and handling.

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Fourth Generation of Firebirds

The fourth generation of Firebirds ran from 1993 to 2002 and was the last generation to hit the market. Advances in motor technology gave Pontiac the ability to put some high-powered options back into the Firebird, calling back to the first and second generation of the car. Though the power called back to earlier generations, the 1993 Firebird was made out of a majority of new parts.

One of the most notable engines from this generation was the LS1 V8, which got up to 325 horsepower. Even besides the more specialized performance-oriented LS1 V8 engine, standard models received a 3.8 L V6 engine from 1996 onwards. This strong engine gave the base Firebird 200 horsepower. Alongside the power options, the Firebird also received anti-lock brakes and airbags to improve the safety of the vehicle.

In 2002, the car went out with a bang, as they released a Firebird Trans Am that featured a WS6 option. With this option added, the 5.7 liter V8 made it so the car could go a quarter of a mile in just over 13 seconds. The 325 horsepower of this final Trans Am made for a powerful car. This Trans Am was also a 35th-anniversary version of the Firebird, featuring yellow paint, custom graphics and black wheels.

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The End of an Era

Even though the final generation of Firebirds got back to their high-powered and high-speed roots, they suffered from a decline in the sports coupe market and a loss in sales. Though the car was still popular with a small audience, GM set aside little funding for the development of new Pontiacs for years and finally ceased production in 2002.

Though the cars are no longer in production, restoration enthusiasts still love to keep the cars on the road, keeping the classic vehicles alive long after they’ve stopped being manufactured. There are tons of aftermarket parts available to assist Firebird owners with restoring their older cars. You can also find plenty of parts and systems that can help you customize the Firebird to your vision.

Fun Facts About the Pontiac Firebird and Trans Am

If you enjoy learning about the history of the Firebird, then you’ll love knowing some of the main facts about the car. Next time you go to a trivia night, you’ll be ready to handle any question about the Firebird by checking out some of the little known facts about the Firebird below:

1. The Trans Am Starred in “Smokey and the Bandit”

A modified Trans Am co-starred with Burt Reynolds in the 1977 movie “Smokey and the Bandit,” making it a cultural touchstone. The Trans Am used in the film was primarily a 1976 model, but it also had its front end replaced by a 1977 model. The movie generated a lot of attention for the car, with Pontiac seeing a significant increase in sales.

2. The Trans Am Also Starred in Other Movies and TV Shows

After starring in Smokey and the Bandit, casting agents recognized the Trans Am’s acting chops. It went on to be featured in the 1979 film “Rocky II,” the 1984 film “Alphabet City,” and continued its roll in the “Smokey and the Bandit” cinematic universe, appearing in “Smokey and the Bandit II” and “Smokey and the Bandit III.” More recently, viewers of the hit TV show, “The Office,” could see the fictional character Dwight Schrute driving around in his 1987 Trans Am in multiple episodes.

3. It Served as the Pace Car for the 1980 Indianapolis 500

The pace car for the 1980 Indianapolis 500 was a 1980 Turbo Trans Am. It was driven by Johnnie Parsons, a retired racer. It’s one of only four Pontiacs to serve as the pace car for the Indianapolis 500.

4. The Pontiac Firebird Was Created by John DeLorean

Most famous for the car he made with his name, John DeLorean originally worked as a Pontiac engineer. At the time, GM management wanted a car to compete with the Mustang and Camaro, leading them to task DeLorean with the responsibility of coming up with the design.

5. The Car Never Reached 400 Horsepower

Even though the vehicle was built to compete with the Chevrolet Camaro, it never reached the power of the rival car. While multiple Camaros have gone over 400 horsepower, the Firebird only ever topped out at 335 horsepower. This lack of high horsepower was likely due to the Firebird’s focus on handling.

6. The Screaming Chicken Decal Arrived in 1973

One of the most famous parts of the Firebird’s design was its decal that got nicknamed the “Screaming Chicken.” Though the decal’s design was created in 1970, it stayed in the shadows until 1973 when a Pontiac designer saw the logo and demanded it be placed on the car. After 1973, it became a very popular feature on the car.

7. It’s Known for Its Exceptional Handling

The Camaro had the edge over the Trans Am in terms of speed, but the Firebird made up ground by providing greater handling. The car’s big tires, large sway bars and low suspension assisted with the car’s handling and made it seriously fun to drive.

8. Most Popular Model Was the 1978 Firebird

The 1978 Firebird was so popular the year it released, that it sold more than any other Firebird ever. It’s no doubt the release of the “Smokey and the Bandit” movie in 1977 helped increase the car’s appeal. This model maintained its staying power, with many buyers interested in it years after its release.

9. The Most Popular Year for the Trans Ams Was 1979

The end of the 1970s was the best for the Firebirds and Trans Am sales. The popular 1978 model was out, and the Trans Am feature in movies and films caused buyers to take an increased interest in the car. This led to 1979 having the highest sales for all Firebirds and specifically for Trans Ams. That year, Trans Am Sales reached 117,109, and total Firebird sales reached 211,454.

10. Least Popular Year for Firebirds Was 1993

While 1978 and 1979 were high points, the car’s sales began to decline, reaching the lowest point in 1993. In that year, only 14,112 Pontiac Firebirds, Formulas and Trans Ams were sold.

11. The First Airbag Came in 1990

It wasn’t until 1990 that a Firebird got an airbag. During an interior design change to the 1990 Trans Am, Pontiac decided to replace the radio control previously featured on the steering wheel with an airbag.

12. The 1969 Firebird Had the Highest Horsepower

One of the earliest Firebirds was also the most powerful. The 1969 Firebird had a WS4 performance package that buyers could add to their car to get a Ram Air IV V8 engine. With this engine installed, it delivered 345 horsepower, higher than any other Firebird that came after it.

13. The Weakest Firebird Was the 1985 4-Cylinder Model

There were a few Firebirds that simply didn’t deliver serious power, with the 1985 4-cylinder model standing out the most. It’s LQ9 2.5L engine only gave drivers 88 horsepower to work with.

14. The First Trans Am Featured a Blue and White Paint Job

If you’re trying to restore an original Trans Am, you can increase its authenticity by outfitting it with its original paint job. The first Trans Am’s body was covered in white paint, and it featured some blue stripes across it.

15. They Didn’t Always Have Pontiac Engines

The Pontiac Firebird didn’t just use Pontiac engines. A few years after the car’s production began, the Firebird started to branch out with the type of engines they used to increase their speed and power. The company began by using Chevy engines but switched over to Oldsmobile and Buick engines in 1976.

Shop Pontiac Firebird and Trans Am Restoration Parts

If you own a Pontiac Firebird or Trans Am, you can find parts for your car at Raybuck Auto Body Parts. We’re car people just like you, and we’re proud to provide all of our customers with high-quality parts at low prices. If you’re trying to restore your classic car, we have your back, as we offer Firebird and Trans Am parts fitting 1967 through 1989 models.

Browse our inventory of Firebird and Trans Am restoration parts today. If you have any questions, don’t hesitate to contact us — one of our knowledgeable staff members will be ready to help.