7.4-Liter LSX454 V8Chevrolet's 454 big block is a legendary engine in muscle car history thanks to its large displacement and low-rpm power. The LSX is a modern interpretation of the 454, boasting 21st-century technology. This crate engine has an all-forged rotating assembly for superior strength, six-bolt cylinder heads for handling increased power, a hydraulic roller camshaft, hydraulic roller lifters, and orange power-coated valve covers.While the engine is sold without most accessories and an intake manifold, it can work with a carburetor or fuel injection. With the single-plane carbureted intake manifold, the LSX454 produces an impressive 627 hp and 586 lb-ft of torque. This brings it closer to the performance of the 9.4-liter ZZ572 engine but with a lower starting price of $14,745.Chevrolet also offered a more powerful LSX454 engine, the LSX454R, with 750+ hp and 680+ lb-ft of torque. At the time, this was the most powerful crate engine rocking a Dominator-type carburetor, a high-rise open-plenum intake manifold, and six-bolt LSX DR aluminum heads with raised ports. While the LSX454R isn't available as a crate engine, the LSX454 can match the output with just a few mods. They include an intake, a camshaft, cylinder heads, and fuel system components.7.4-Liter ZZ454 V8General Motors' ZZ454 is a V8 crate engine boasting 7.4 liters of displacement. GM offers two ZZ454 variations: the 454 HO and ZZ454/440. The ZZ454 promises enthusiasts affordable power, with the 454 HO producing 438 hp at 5,300 rpm and 500 lb-ft of torque at 3,500 rpm. Despite its impressive performance, the 454 HO has a starting price of $8,971, with the ZZ454/440 starting at $10,095. The ZZ454 engine boasts a solid foundation with block casting, an all-forged rotating assembly, and four-bolt main caps. General Motors also fits a smooth hydraulic roller camshaft, improving the ZZ454's performance range and drivability.In the more powerful ZZ454/440, GM opts for oval port aluminum heads, upping the performance with 30 hp and 19 lb-ft of torque. GM ships these engines with an aluminum intake manifold, balancer, water pump, and a 14-inch flex-plate. However, to get the engine running, you need additional accessories like a starter, carburetor, and ignition system from Chevrolet Performance. Surprisingly, the ZZ454 can handle some performance upgrades, including aluminum cylinder heads, hardened push rods, a crank pulley, and a supercharger, which can help bump the performance to over 700 hp.7.5-Liter Oldsmobile 455 V8While the Oldsmobile nameplate is no longer in the modern automotive market, the iconic brand gave enthusiasts vehicles like the 422, Cutlass, Tornado, Vista Cruiser, 88, and 98. It became overshadowed by other GM brands like Pontiac and Chevrolet, but it also produced one of the mightiest V8 engines of the '60s, the 455 V8. Oldsmobile's 455 V8 was a second-generation design, succeeding the original Rocket engine, which was around for 15 years.After its debut in 1968, this was the largest engine on offer, boasting a higher deck and a longer stroke than small block V8s. At the time, Oldsmobile manufactured different variants of the 455 V8, some with altering piston designs, compression ratios, and intakes. Because of this, the output varied between 310 to 400 hp and 500 lb-ft of torque. The Oldsmobile 422 had a W30 package producing 370 hp. Despite having lower performance figures than its predecessors, this W30 package featured the 455 V8 with an aluminum intake manifold, forced air induction, and forged connecting rods.The 1970 Tornado GT was one of the most powerful vehicles to feature the 455 V8, producing 400 hp. This engine had bigger intake valves, cast aluminum pistons, and a more aggressive hydraulic lifter camshaft. In the '70s, the performance figures of the 455 V8 decreased due to the strict emission regulations. Nowadays, the 455 V8 still lives on as an excellent option for buyers looking for a capable engine to use on their street builds.9.4-Liter ZZ572 V8The ZZ572 is a 9.4-liter V8 engine available in two configurations: the 620 Deluxe and 720R Deluxe. These are among the most powerful V8s from GM, but they're only available as crate engines, ideal for use in custom builds like Ernie Miyamoto's 1972 Volkswagen Super Beetle. The 620 Deluxe produces 621 hp and 645 lb-ft of torque, making it suitable for the street and drag strip. It boasts a forged crankshaft, aluminum rectangular port heads, and raised exhaust ports. Fortunately, this ZZ572 engine also has a fully assembled bottom, allowing you to fit an induction system of your choice. In addition to its impressive performance, the ZZ572/620 Deluxe engine commands a price premium of $19,664.GM also offers a more powerful 720R Deluxe engine, boasting 727 hp and 680 lb-ft of torque. This is an excellent alternative for enthusiasts looking to build a sub-10-second car. Like the 620 Deluxe, the ZZ572/720R Deluxe has a higher starting price of $20,359. While GM offers the ZZ572 with a Dominator-style 1,150-cfm carburetor, buyers should add accessories like a starter, transmission controller, and fuel pump to get it running.