With today’s super-efficient turbocharged inline and V6 engines it can be a real eye opener when you realize just how much raw displacement was needed to make similar horsepower back in the muscle car heyday. Engine displacement grew at a rapid pace as the horsepower wars of the 1960s exploded, culminating in some seriously large displacement big block engines from the Big Three (that also happened to be seriously large in size as well). While all three manufacturers offered 400 plus cubic inch big blocks, it would be GM’s 454ci big block (a 7.4 liter Chevy engine) that saw the largest production numbers and applications. Found in everything from the Corvette and Chevelle to full size trucks, commercial equipment like RVs and busses and even marine craft. Today, even with the popularity of stroker engines, turbos, and other power making enhancements, the idea of a 454 swap in a muscle car, classic truck, or hot rod is still just as popular as ever.

General Motors’ big block engine program launched with the Mark I “W-engine” platform in 1958. The Mark II was a race only engine that never saw production use, and the Mark III big block never got past the GM engineering department’s desk due to high tooling costs. So, in 1965 the Mark IV big block entered production. Not to be confused with the Gen IV small block (or the Chevy 454 LSX for that matter), all big block Chevy engines used the “Mark” naming convention through the fourth generation, then switched to “Gen” for V and up. Hey, don’t shoot the messenger, but if you want to be taken seriously in the GM big block bench racing sessions, with your friends, don’t call the Mark IV big block a “Gen IV big block.” You’ve been warned.

The top dog 427 big block, found in the Corvette, would soon be replaced by an even bigger engine, the mighty 454!

The new Mark IV big block provided enthusiasts with the popular 396 and 427 big blocks of the era. But it would be the 454 entering the chat in 1970 (using the same 4.25-inch bore as the 427, but with a longer 4.00-inch stroke) that many remember and still lust after to this day. The LS-7 model of the 454 would take top horsepower honors over it’s smaller big block brothers, including the famed ZL1 aluminum 427, with 465 peak horsepower compared to the 427 ZL1’s 430 horsepower. GM would later offer the LS-7 as a crate engine rated at 500 horsepower. The Mark IV version of the 454 would run through 1990 in GM trucks, vans, and commercial chassis, after which it was replaced by the Gen V 454 L19 engine offering in 1991 through 1995 in GM trucks.

The Gen V (not the Mark V!) would see four-bolt main caps, whereas the earlier Mark IV blocks could be two bolt or four bolt depending upon the application, one piece rear main seal, cast aluminum valve covers and timing cover for better gasket sealing, and a host of other updates. Obviously, by this time the engines were using fuel injection, though the Gen V did not get roller lifters/cam set up. That wouldn’t arrive until the Gen VI big blocks (454 Vortec or 7400 Vortec). The Gen V also was fitted with a non-adjustable valvetrain. Thankfully, the Mark IV and Gen V 454 big blocks do carry enough commonality that mixing and matching parts is easy to build the 454 of your dreams (or at least what your budget can afford. Our build list ideas below will focus on the Mark IV variant, but if you stumble across a Gen V for a can’t pass it up price, by all means use the Gen V for your 454 build on a budget. But first, some Chevy 454 specs for you to consider.

Mark IV 454 | LS-5 454 Specs | 454 LS-6 Specs | LS-7 Specs

The 454 big block Chevy was the last engine in the Mark IV family to be introduced. It debuted in 1970 using the same 4.25-inch bore as the 427, but with a longer 4.00-inch stroke. The 454 would be offered in all manner of cars and trucks and in various iterations as well until the engine was phased out in 1976 due to unleaded fuels, fuel economy standards, and emissions regulations. The 454 Mark IV can be found in the following applications:

1970–1974 Chevrolet Corvette
1970–1975 Chevrolet Chevelle
1970–1975 Chevrolet El Camino
1971–1975 GMC Sprint
1970–1975 Chevrolet Monte Carlo
1970–1976 Chevrolet Caprice

Below we’ve broken down the LS-5 and LS-6 Chevy 454 specs, as they are the most widely sought 454 versions. The LS-4 and later mid-80s L19 are options as well, just not as widely produced and with lower stock 454 hp. We’re including the LS-7 as well here, even though it never made it into a production vehicle and ultimately ended up as a GM crate engine.

LS-5 454

The LS-5 version of the 454 big block Chevy was introduced in 1970 for the Corvette, Chevelle, El Camino, and others as part of the SS454 package. The engine would see a high of 390 horsepower in the 1970 Corvette, to a low of 270 horsepower in 1972 with the change to SAE net power ratings and a drop in compression for emissions reasons.

LS-5 454 big block Chevy engine specs for the 1970 model year.

LS-6 454

Released the same year as the LS-5, the LS-6 was the top dog as far as stock 454 hp went. Found in the 1970 Chevelle SS 454, it provided the owner with 450 horsepower and the same earth twisting 500 lb-ft of torque. In the horsepower vs torque argument, remember, it’s torque that gets you going, especially welcome in a heavy muscle car of the time like the ’70 Chevelle. It was rare to see a GM muscle car with more horsepower than the Corvette, but it happened in 1970. The LS6 454 specs would lose 25 horsepower (down to 425 and “just” 475 lb-ft of torque) due to the compression dropping from 11.25:1 to just 9.0:1 the next year. However, the 1971 LS-6 could only be had in the Corvette in its final year. That’s right, the LS-6 was only available in 1970 and 1971.

LS-6 454 big block Chevy engine specs for the 1970 model year. *aluminum head on Corvette

LS-7 454

The LS-7 version of the 454 was to be a 465 horsepower exclamation point at the end of the 454 big block Chevy production sentence and only available in the Corvette. However, even though a few made their way into test vehicles, the LS-7 version of the 454 never made it to the assembly line. Originally planned for a tri-power setup, and then a single Holley 840-cfm four-barrel, the LS-7 454 ended up becoming an over the counter crate engine that could be purchased at your local Chevy dealership, due in part to rising insurance rates, unleaded fuel mandates, and increased emissions standards. Our spec chart reflects the crate engine version.

LS-7 454 big block Chevy engine specs for the 1970 model year.

Gen V 454 | L19 Specs

Introduced in 1991, the Gen V (again, note the change from the previous Mark nomenclature) designation was created due to the engineering changes to the Gen V 454 specs for the engine block casting. These updates include a one piece rear main seal, relocation of the main oil gallery, removal of the mechanical fuel pump mount, and all castings now using four bolt main caps. The rest of the Gen V updates were in the valvetrain with the use of a hydraulic flat tappet cam (vs the solid lifter setup seen in many of the Mark IV variants) along with non-adjustable bolt down rocker arms covered by new cast aluminum valve covers that sealed with an O-ring gasket. The L19 454 engine was rated at 230 horsepower and 380 lb-ft torque and found in GM’s 2500 and 3500 pickups and famously in the 1991-1993 454SS pickup model. It was discontinued after 1995, with the introduction of the L29 engine (Gen VI/Vortec 7400) in 1996. While a ”454 peanut port build” isn’t as powerful as starting with the earlier Mark IV, for a budget starting point don’t count out the Gen V.

L19 454 big block Chevy engine specs for the 1991 model year.

454 Build on a Budget

If you ask 10 friends, you’ll get 10 different answers as to what a “budget build” may be. But for argument’s sake we’re going to define a budget 454 build big block Chevy as one that uses as many original or stock replacement parts as possible with as much labor as possible handled by the owner. Obviously, there are factors, such as machine work, which come into play with this that simply can’t be avoided. However, some standard machine shop practices, such as installing cam bearings, tapping the block for screw in plugs, and others can be handled as a DIY in the home shop with a rental tool or tools borrowed from a friend that does a lot of engine work.

The better the engine you start with the less you’ll most likely have to spend. But let’s be honest here, most of these Mark IV big blocks are 35 years old or older with high mileage and possibly already a rebuild or two on them, so expect an overbore and new pistons at the least if you need to go inside the short block. Otherwise, if you find a solid running, yet stock, 454 from a truck (or even a stationary generator or farm use application) you can stick with bolt-on parts to enhance your budget 454 build, such as aluminum cylinder heads, aluminum intake with four-barrel carburetor (you’ll find great solutions in our BBC top end kit offerings), large primary long tube headers, and even a cam swap to make some great power and torque for a 400 hp 454 build for not all that much money.

It’s easy to want that deep sump flashy race oil pan, cast aluminum valve covers, and serpentine accessory drive conversion. However, for a budget build it is completely acceptable to reuse the engine’s “tin” and V-belt accessory drive, stock flywheel/flexplate, and other bits to put your budget build money where it counts with high flow induction, a performance camshaft, new oil pump, BBC fuel pump, and water pump, and so forth. When it comes to budget/junkyard 454 big block build, it doesn’t have to be pretty, it just has to make horsepower!

Junkyard 454 Build Bolt-Ons

The true goal of a junkyard 454 build is to have a running (and dependable) cheap 454 build for as low as financially possible. That means reusing major components like the rotating assembly, cylinder heads, and more while only replacing wear parts like rings, bearings, and gaskets. This leaves a little room in the budget for something like a swap meet intake and carb find, or some long tube BBC headers, but otherwise we’re not talking aftermarket aluminum heads, roller cam and lifter conversion, and so forth. Sticking with your basic “re-ring” project with fresh bearings, a little polish to the crank journals, and a new oil pump, you should have a solid running junkyard 454 stump puller to give your project some motivation. Then, as your budget allows, you can plan for a nice rebuild with those fancy aluminum 454 heads, and more down the road or to upgrade to one of our big block Chevy crate engines.

375 HP-400 HP Budget 454 Build Recipe

375-400 HP Budget 454 Build Parts List components using stock block and rotating assembly.

500 HP-550 HP Budget 454 Build Recipe

500-550 HP Budget 454 Build Parts List components using stock block.

600 HP-800 HP 454 Build Best Practices

Once you go north of 600 horsepower in a big block Chevy build parts selection becomes a bit more critical. Not just for the sake of making power, but for longevity of the engine as well. Lots of rpm, lots of compression, lots of cam lift, all get things moving around. You want to use quality fasteners, four-bolt main caps (or an aftermarket block) and adhere to stringent torque specs. Building a 454 stroker motor is certainly the smartest starting point here if you’re looking to exceed a 500hp 454 build

When in doubt, stroke it out! How about 632 cubes from a big block Chevy casting that makes 815 HP!

You can take our 500 HP 496ci stroker build above and tweak the components, as we did for our 600 HP 454 build found in our Week to Wicked Nova Gasser (648 HP to be exact), or simply add some nitrous to gain that extra 100-200 horsepower you’re looking for. If you’re looking for ultimate power peep our 454 Chevy crate engine offerings making up to 815 horsepower!

454 High Torque Build

When it comes to certain applications, such as 454 towing build or even a race boat 454 engine build, the primary focus will be on torque and not all out 454 big block hp. For these applications, a 454 high torque build should be your game plan. Gaining additional torque in your big block Chevy can be accomplished with the right 454 cam. The cam is the heart of any engine build and will dictate torque and at the rpm at which it will peak. Pairing this with the right 454 intake manifold, long tube headers, and other torque building components you can easily exceed 500 lb-ft of torque without much effort. Once again, a stroker engine build, or adding a power adder like nitrous will also increase torque, just remember you want the torque curve to come in low and be as broad as possible.

If your budget allows, upgrading to an aftermarket performance aluminum cylinder head will really allow your big block Chevy to breathe deeply.

Best Big Block Chevy Heads for the Money

No matter the displacement, the key to making power with any engine is airflow. Getting the maximum amount of air (and matching fuel) through the combustion chamber. From the carburetor or EFI and intake on the inlet side, to the manifolds/headers and exhaust piping on the outlet side, it all plays a vital role in maximizing airflow. Installing a big carburetor and single plane intake along with big tube headers won’t be as affective on restrictive stock heads as they would be on higher flowing aftermarket heads that have redesigned combustion chambers, larger valve sizes, and higher flowing intake and exhaust ports. Below we have listed some of the best heads for 454 big block builds to help your 454 big block hp build take a deep breath when you bury the loud pedal into the firewall.

Edelbrock Performer RPM and Victor Jr.

Edelbrock is a reputable brand, and their Performer RPM and Victor Jr. heads are designed for high-performance street and racing applications.
These heads offer good power gains and are assembled with quality components.

Flo-Tek

Flo-Tek is known for producing high-quality heads at a value price
Cylinder head options are popular among performance enthusiasts on a budget.
Features efficient combustion chambers and good flow characteristics.

Airflow Research (AFR) Enforcer

AFR heads are well-regarded for their performance and airflow capabilities.
The AFR 335cc heads are suitable for big block Chevy stroker engines, providing excellent flow for 500 plus cubic inch builds.

Best 454 Camshaft for a Budget Build

There are many variables to consider before choosing a camshaft for your 454 big block Chevy build. What is the compression ratio of the engine? Are you retaining the stock hydraulic flat tappet (or even mechanical) cam setup, or upgrading to a roller cam retrofit? Will the engine be fuel injected or carbureted? Of course, the actual use of the engine is a key factor as well. Is your 500 hp 454 budget build going into a 2,800 lb. hot rod that is a street cruiser, or a 3,600 lb. race car? Or perhaps even a 4,000 lb. pickup or as part of a dual engine marine setup? As you can see, there are too many factors at play here to provide a de facto camshaft solution that will work for all cases. That said, for most of the enthusiasts reading this, we have picked a couple of nice street friendly hydraulic flat tappet camshafts that will provide a broad torque curve for most applications.

Comp Cams 11-205-3 High Energy Hydraulic Camshaft

Duration @ 0.050": 218° intake / 218° exhaust
Lift: 0.485" intake / 0.485" exhaust
Provides good mid-range torque and is suitable for a budget-friendly build.

Edelbrock 2162 Performer-Plus Camshaft/Lifter Kit

Duration @ 0.050": 218° intake / 228° exhaust
Lift: 0.500" intake / 0.500" exhaust
Designed for high-performance street applications, offering a good balance of power across the RPM range.

Helpful Tools for Your 454 Big Block Build

Having the proper tools to overhaul your big block Chevy is important to getting the job done correctly.

Whether this is your first engine build, or your 50th, there will always be a few tools you’ll need specific to an engine or engine family. If you’ve not heard the adage about borrowing a tool, we’ll repeat it here: If you have to borrow a tool more than twice it’s time to buy your own! With that thought in mind, we’ve amassed a few of the tools you’ll need to properly build your own 454 big block Chevy and fit it to your project car or truck.

Must Have Modifications for a 454 Swap

If you’re building a 454 big block Chevy to install into your early Camaro or Chevelle the installation is straightforward since these vehicles came with the big block Chevy as an available option. In other applications you may have to do some fabrication to provide room for such a large engine to fit between the front frame rails. A blown big block Chevy in a ’32 Ford is certainly a beautiful sight, but it’s not just going to bolt right in like a 1970 Chevelle. With that in mind we wanted to provide a list of areas that may require attention when fitting a big block Chevy into your ride.

Engine bay modifications for engine clearance
Conversion Motor mounts, or adapters to fit the engine
Upgraded chassis stiffening/support for strength
Improved braking and suspension to handle the weight of the big block engine
Fuel system upgrades, such as 3/8 fuel line to handle the engine’s fuel demand
Heavy duty drivetrain improvements (we suggest a manual as the best transmission for 454 big block swaps)