Big Block Performance Engines


The Classic L88 427 Updated For The 21st Century!

Between 1967 and 1969, the legendary L88 was the ultimate expression of Chevy’s Big-Block power, combining a rigid iron cylinder block with lightweight aluminum cylinder heads and a single four-barrel carburetor. That raspy rat engine was rated at 480 horsepower, although the figure was generally thought to be on the conservative side.

Chevrolet Performance has recreated that classic Big-Block combination in the ZZ427/480 – including the 480 horsepower rating (and it just might be a little on the conservative side, too). Like the original, it features a forged steel crankshaft and high-flow, oval-port aluminum cylinder heads.

We’ve upgraded the camshaft from the original’s mechanical flat-tappet design to a smoother hydraulic roller, which delivers great drivability characteristics and a broader rev range. A 10.1:1 compression ratio means it will perform great on pump gas, too.

Whether you’re building a ’69 COPO Camaro resto-mod tribute, a modified mid-year Corvette or a street-tire class winner, the ZZ427/480 is the heritage-inspired crate engine that delivers the performance that built the Big-Block’s legendary reputation.


It's 1970 all over again!

Chevrolet Performance’s 454 HO crate engine is classic in its own time, offering enthusiasts an affordable Big-Block combination with performance specs that will make you think it’s 1970 all over again – with 425 horsepower and 500 asphalt-wrinkling lb.-ft. of torque.

The foundation of the 454 HO is a brand-new, updated cylinder block, which incorporates many strength and performance design enhancements – making it a smart and economical alternative to rebuilding. We also add an all-forged reciprocating assembly for maximum durability, a roller camshaft and a set of rectangular-port iron cylinder heads.

We deliver the 454 HO with a water pump, balancer, 14-inch flexplate and aluminum intake manifold. Add a carburetor, ignition system and starter and your budget Big-Block will be ready to roar. All of the necessary parts are available from Grizzly Trail Motors.


Oval-Port Aluminum Heads Deliver Big Power In An Affordable Package!

Our engineers took the 454 HO – with its super-tough, all-forged reciprocating assembly – and matched it with a set of higher-flow, oval port aluminum cylinder heads to pick up an additional 15 horses, while still offering 500 lb.-ft. of torque. We dubbed it the ZZ454/440 and it’s an affordable high-performance Big-Block for any chassis you can stuff it in.

The ZZ454/440 uses our new cylinder block casting for greater strength and performance, while the aluminum heads use smaller, 110cc combustion chambers to boost compression to 9.6:1, up from 8.5:1 on the 454 HO. We then match the airflow capability with a high-lift, hydraulic roller camshaft that delivers great idle quality and requires no periodic lash adjustments.

Our crate engine package includes the ZZ454/440 assembled with a water pump, balancer, aluminum intake manifold and a 14-inch flexplate.

Grizzly Trail Motors can hook you up with the carburetor, starter, ignition system and other accessories required to get this big power Big-Block started.

ZZ502/502 Deluxe

Our Most Popular Big-Block Crate Engine For The Street And Strip!

Chevrolet Performance’s ZZ502/502 is one of the industry’s benchmark crate engines, offering excellent value with a proven combination of performance that is suitable for the street or strip. With more than 500 horsepower and 567 lb.-ft. of torque, it demands your full attention and a chassis that is strong enough to harness its frame-straining twisting power.

All ZZ502 crate engines are manufactured with GM’s updated cylinder block casting that is stronger and better supports high-performance applications. A forged crankshaft, along with forged rods and pistons, anchors the bottom end, while our popular oval-port aluminum heads offer excellent airflow characteristics. Torque tops the 500 lb.-ft. mark by approximately 2,500 rpm and doesn’t dip below it until about 5,000 rpm.

Our ZZ505/502 Deluxe package comes complete from the oil pan to the carburetor, including an HEI distributor, plug wires, starter, water pump, balancer and an aluminum intake topped with a Holley 870-cfm four-barrel.

We’ve taken care of the engine’s details. You need to make sure your car can handle the ZZ502/502!


Affordable Big-Block Performance with huge torque and 450 HP!

With 450 horsepower and 550 lb-ft of torque, our 502 HO crate engine has power on tap for every need -- whether it's a '69 Chevelle at the drag strip or the Suburban that towed it there!

The 502 HO is all about torque. It hovers just below the 500 lb-ft level by 2800 rpm, remaining there through 4200 rpm. All those axle-twisting pound-feet are rooted in a stronger, updated four-bolt cylinder block that houses a forged steel crankshaft, forged and shot-peened rods, and forged aluminum pistons. In other words, it's a super-stout assembly that is as durable as it is powerful.

Iron, rectangular-port cylinder heads keep the 502 HO affordable, and our crate engine assembly includes an aluminum dual-plane intake manifold, a water pump, 14-inch flexplate, balancer, and more. You add the carburetor, starter, and ignition system - all available at Grizzly Trail Motors.

ZZ572/620 Deluxe

The Most Powerful Big-Block Street Engine From Chevrolet Performance!

The ZZ572/620 is the ultimate expression of Chevrolet Performance’s engineering capability. We build the ZZ572 with huge 4.560-inch bores and add a forged 4.375-inch-stroke crankshaft. To make sure those cylinders are packed with every cubic centimeter’s worth of atmosphere, we use a camshaft with incredible 0.632/0.632-inch lift and 254°/264° duration specifications.

Aluminum rectangular-port heads with 310cc intake passages complement the airflow capability offered by the big-bore bottom end. They also feature 118cc raised exhaust ports and 118cc combustion chambers. The valves are big, too – measuring 2.250 inches on the intake side and 1.880 inches on the exhausts.

Grizzly Trail Motors delivers the ZZ572/620 Deluxe with an 850-cfm carburetor, HEI distributor, aluminum water pump and distinctive orange powder-coated valve covers that proudly proclaim the 572 legend.

Z572/720R Deluxe

The ultimate beast!

Make no mistake, the ZZ572/720R is a race motor. It delivers a resounding 720 horsepower and 685 lb.-ft. of torque creating at the same time the most powerful big-block crate engine ever offered by GM Performance Parts.

We took the ultra-popular ZZ572/620 pump gas street engine added 12:1 compression pistons, a hotter camshaft, and our rectangular-port aluminum Bowtie heads with stiffer valve springs to work with the new cam. The block is the Gen VI tall-deck Bowtie block, which was designed for the 572 application. The solid roller camshaft is a .714 lift magic maker that aggressively feeds the air/fuel mixture into the hungry, high-squeeze, stroker big-block. This creates a rev-happy monster that rocks to a 6750 rpm redline, leaving the competition in its wake.

The ZZ572/720R is rated at 720 horsepower at 6250 rpm and 685 lb.-ft. of torque at 4500 rpm. The short block is built with the best heavy-duty parts in the GM Performance Parts part bin, including a 4340 forged steel crankshaft, shot-peened forged steel rods, forged aluminum pistons with full-floating wrist pins, stiff dual valve springs, and a louvered oiling windage tray. Our Deluxe ZZ572/720R ships with a Holley 1090 Dominator-style carburetor, tall-deck single-plane intake manifold, HEI distributor, aluminum short-style water pump, and 8mm spark plug wires. Distinctive '572 CHEVROLET' cast aluminum valve covers complete the package. GM Performance Parts integrated, durability-tested, and validated this combination to the described performance levels, and all you need is a GM Performance Parts lightweight starter to fire it up!


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  • Product may not be exactly as illustrated.