Dart 427

Big-inch small-blocks used to be exotic high-dollar propositions. They’re still exotic, but Dart has made it much more affordable to plop one in your muscle car. The company has been designing its blocks to play nice with big-bore, long-stroke rotating assemblies for quite some time, and it’s now using that know-how to build its own short-blocks. The foundation of the Dart 427 Chevy is an SHP block bored to 4.125 inches. It’s fitted with a forged rotating assembly with the option of either flat-top or -20cc pistons. All you have to do is throw on some heads and an intake, and this thing’s ready to rip. With a set of Dart Pro 1 heads and a mild hydraulic roller cam, Dart says the 427 will dish out 550 hp on the dyno.

Dart Machinery
248.362.1188 · dartheads.com

Specifications
Cubes: 427
Bore/Stroke: 4.125x4.000 inches
Output: 550 hp and 550 lb-ft
Block: Dart SHP iron
Crank: Dart 4340 forged steel
Rods: Dart forged steel
Pistons: Forged flat-top or -20cc dish
Cylinder Heads: None
Intake: None
Warranty: None
Price: $5,398

Summit/Chevrolet Performance LS 327

Who says you need to go broke to jump on the LS bandwagon? Available through Summit Racing, this Chevrolet Performance LS 327 long-block offers big bark out of a small package. It’s essentially the same durable 5.3L motor that powers millions of fullsize GM trucks and SUVs. Based on a rugged six-bolt iron block, the LS 327 is fitted with a nodular iron crank, powdered metal rods, and 9.5:1 hypereutectic pistons. Capping it off are cathedral-port aluminum heads capable of flowing well over 300 cfm when fully ported. Since it’s sold as a long-block, sourcing an intake manifold and water pump is up to the end user. If it sounds like a perfect recipe for some mild boost, you’d be correct in your assessment. Boosting one of these long-blocks to 8 psi is good for well over 500 hp, and the stock-block can handle 1,000 hp without a hiccup.

Summit Racing Equipment
800.230.3030 · summitracing.com

Specifications
Cubes: 327
Bore/Stroke: 3.780x3.622 inches
Output: 327 hp and 347 lb-ft
Block: Factory GM iron
Crank: GM iron
Rods: GM 6.098-inch powdered metal
Pistons: Hypereutectic 9.5:1
Cylinder Heads: GM cathedral-port aluminum
Intake: None
Warranty: Two years, 50,000 miles
Price: $3,789

Speedway/BluePrint 496

Big-block Chevys have always been associated with big power and big money. Fortunately, thanks to Speedway Motors and BluePrint engines, you can now step up to big-block power without going broke. Available exclusively through Speedway Motors, this 496 produces 590 hp for just $6,999. The combo starts life as a GM Mark IV block, and after boring it 0.060-inch over, BluePrint stuffs it with a forged crank and rods, and 10.1:1 hypereutectic pistons. Aluminum rectangular-port heads and a dual-plane intake provide the airflow, and a 242/248-at-0.050 hydraulic roller cam actuates the valves. The 496 comes complete with the exception of a water pump and carb. Finally, there’s now an affordable way to lay some big-block–style patch.

Speedway Motors
800.979.0122 speedwaymotors.com

Specifications
Cubes: 496
Bore/Stroke: 4.310x4.250 inches
Output: 590 hp and 600 lb-ft
Block: Factory Mark IV iron
Crank: Forged 4340 steel
Rods: Forged H-beam
Pistons: Hypereutectic 10.1:1
Cylinder Heads: Aluminum rectangle port
Intake: Aluminum dual-plane
Warranty: 30 months, 50,000 miles
Price: $6,999

Competition Products 383

While it’s certainly possible to build much larger small-blocks these days, the good ol’ 383 keeps chugging along. The same balance of performance and value that made it popular decades ago still applies today, and Competition Products’ 383 proves the point. For a little over $4,000, it kicks out 410 hp and 450 lb-ft. The company starts with a four-bolt block, punches it 0.030-inch over, then fits it with a cast Scat crank, steel rods, and 9.5:1 hypereutectic pistons. The short-block breathes through aluminum cylinder heads, a dual-plane intake, and a dyno-tuned carb, all from Edelbrock. All you have to add is a water pump, and this puppy’s ready to fire up.

Competition Products
800.233.0199 competitionproducts.com

                                                                                                                   
Specifications
Cubes:383
Bore/Stroke:4.030x3.750 inches
Output:410 hp and 450 lb-ft
Block:Factory GM iron
Crank:Scat cast steel
Rods:Scat 4340 forged steel
Pistons:Hypereutectic 9.5:1
Cylinder Heads:Edelbrock aluminum
Intake:Edelbrock Performer RPM
Warranty:One year, 12,000 miles
Price:$4,175