Chevy 454 Big Block: Specs, Horsepower and 454 Crate Engines
The Chevy 454 is a 7.4-liter (454 cubic inch) big block V8 with a 4.250″ bore and 4.000″ stroke, introduced for the 1970 model year and built in Chevrolet cars, trucks, motorhomes and boats for three decades. Its size and torque made it the signature muscle car engine of 1970, and it remains one of the most popular big blocks for swaps and new crate engines.
454 big block specs
| Specification | Chevy 454 |
|---|---|
| Displacement | 7.4L (454 cubic inches) |
| Bore x stroke | 4.250″ x 4.000″ |
| Family | Chevrolet big block (Mark IV, later Gen V and Gen VI) |
| Valvetrain | Overhead valve, two valves per cylinder |
| Firing order | 1-8-4-3-6-5-7-2 |
| Years | 1970 model year until GM trucks moved to the 8.1L in 2001 |
The GM Performance BBC 454 bare block (part 19170538) shows the dimensions: a 4.250″ bore, 9.800″ deck height, 4-bolt main caps and a one-piece rear main seal. Firing order and cylinder numbering are covered in our Chevy firing order guide.
How much horsepower does a 454 make?
It depends heavily on the year and version:
- 1970 muscle cars: the top LS6 version was rated at 450 HP (gross) in the Chevelle SS 454.
- 1970s: ratings fell as compression was lowered for emissions and manufacturers moved from gross to net ratings.
- 1990s trucks: the Gen V and Gen VI (Vortec 7400) truck 454s were rated at roughly 230 to 290 HP, with strong low-RPM torque for towing.
- New crate engines: the GM Performance 454 HO (part 19433409) is rated at 438 HP. BluePrint’s 454 comes as a long block, dressed, or EFI, with the rating shown on each product page.
454 vs 427, 502 and 572
| Big block | Bore x stroke | Liters |
|---|---|---|
| 427 | 4.250″ x 3.760″ | 7.0L |
| 454 | 4.250″ x 4.000″ | 7.4L |
| 496 (stroker) | 4.310″ x 4.250″ | 8.1L |
| 502 | 4.466″ x 4.000″ | 8.2L |
| 572 | 4.560″ x 4.375″ | 9.4L |
The 454 shares the 427’s bore but has a longer stroke, so it makes more torque. The 502 keeps the 454’s stroke with a much larger bore, and the 572 grows both. New big block crate engines in our range include the GM 502 (461 HP), ZZ502 (508 HP), ZZ572/620 (621 HP), 572/720 (720 HP) and the BluePrint 632 Pro Series (815 HP). See all big block Chevy crate engines.
Building or stroking a 454
- Blocks: the GM 454 block lists an intended maximum finish bore of 4.310″, and GM also offers a Gen VI big block with a 4.500″ bore. See engine blocks.
- Stroker kit: the Eagle BBC 496 stroker rotating assembly combines a forged 4.250″ stroke crankshaft with forged pistons for a 4.310″ bore and 6.385″ H-beam rods, balanced, which turns a 454-size block into a 496.
- Connecting rods: Bill Miller Engineering aluminum rods for big block Chevy are listed under rotating assemblies and internals.
Before you put a 454 in a car
A big block is wider, taller and heavier than a small block, so check hood and exhaust clearance, engine mounts, cooling capacity and whether your transmission and rear axle can take the torque. If weight or space is tight, compare small block Chevy crate engines such as the 383 stroker. Our big block vs small block guide compares the two families.
Frequently asked questions
Is a 454 a 7.4?
Yes. 454 cubic inches is 7.4 liters, and GM’s later truck versions were sold as the Vortec 7400.
How much horsepower does a 454 big block have?
Factory ratings ranged from 450 HP (gross) for the 1970 LS6 to roughly 230 to 290 HP for 1990s truck engines. The new GM Performance 454 HO crate engine is rated at 438 HP.
What is the difference between a 454 and a 427?
Both use a 4.250″ bore. The 454 has a 4.000″ stroke against the 427’s 3.760″, which adds 27 cubic inches and more torque.
Can you stroke a 454?
Yes. A 4.250″ stroke crankshaft with a 0.060″ overbore (4.310″) makes about 496 cubic inches, which is what the Eagle 496 stroker kit does.
What is a ZZ572?
The ZZ572 is GM Performance’s 572 cubic inch (9.4L) big block Chevy crate engine, with a 4.560″ bore and 4.375″ stroke. We list the ZZ572/620 Deluxe (part 19331583), which GM rates at 621 HP and 645 lb-ft even though its name says 620, and the 572/720 (part 19331585), rated at 720 HP. Check each product page for what is included.
Related: 454 crate engines, big block vs small block, Chevy 350 engine, what is a stroker engine, crate engine prices, long block vs short block, 427 engine, liters to cubic inches, all guides.
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