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572ci Big-Block - Mail-Order Strokers

Admit It, You've Always Lusted for a 572ci Big-Block and Now's Your Chance

By , Photography by Manufacturers

There are times when a junkyard 350 or even a 6.2L aluminum LS engine just isn't enough. There's an ever-growing portion of the Car Craft population that embraces wretched excess, grabs ahold of ludicrous-sized engines, and puts the power down with tire-wrinkling acceleration. The players in this vignette are not stars of the quarter-mile—they are street-burners like us. But they know that massive displacement is what shakes the ground, and there's only one real way to get there. Spend the money on a good aftermarket block, a long-arm crank, and rods, add a great set of heads, and you have the recipe for an axle-twister. Sure, you can add a centrifugal supercharger like an F2R Procharger or an 8-71, or even a pair of hair dryers for ludicrous power, but frankly an 11:1 compression 572ci Rat with rectangle port heads and a big roller cam doesn't need a turbo to flatten your eyeballs to the back of your head when you hook all that torque to a stretch of 1,320 feet of asphalt.

We've been doing some part-number archaeology and discovered that building a big-inch Rat motor has never been easier and less expensive to build than right here, right now. Sure, you'll spend $10,000 for a carburetor-to-oil-pan big-inch Rat, but these durable parts will deliver righteous power for as long as you want, and the most you might have to do is change the oil. Then when you become cozy to all that power, add a 150 shot of nitrous and that good old feeling will come right back. While 1,000+ hp looks attractive, unless you have an NHRA 25.5 chassis certification to run 7.50 at 180 mph in the quarter, along with all the other safety gear that turns your cruiser into a race car with a rollcage, it seems counterintuitive to pay for 2,500 hp you can't really use. But you can run 10 flat at 138 mph with little more than a few safety pieces and a five-point rollbar. So roll back the ridiculousness a little and let's look at what it takes to build an affordable, normally aspirated big-inch Rat motor. It's easier than you think.


Cylinder Blocks

Any big-inch Rat worth its head studs begins with a good foundation. We've just finished assembling a 496ci Rat based on a stock 454 block, and frankly, we should have spent the extra money for an aftermarket block—one with a 4.50-inch bore. Factory 454 blocks are fine at 700 hp, but if you are serious about building an axle-twisting Rat, then invest in a good block. Chevrolet Performance, Dart, World, and now Blueprint Engines all offer new castings that can get the job done. A critical point is choosing the bore size. This is where bigger is always better. The minimum you should consider is 4.50 inches. Besides better breathing from the larger bore, the advantage is to create a big-inch engine without having to add the longer stroke, which increases piston and ring wall friction and windage. You can build a 555ci Rat with a 4.56-inch bore, while keeping the stroke to 4.25 inches.


Block Party Numbers

Description Bore Deck Height Weight PN Price
Dart one-piece 4.50–4.625 9.80 250 31273444 $2,250.78
Dart two-piece 4.50–4.625 9.80 250 31273644 2,250.78
Chevy one-piece 4.50 max 9.80 269 19170540 2,299.97
Chevy one-piece 4.50–4.600 9.80 258 19212192 1,869.97
Blueprint two-piece 4.50–4.625 9.80 275 BPS4500200S 2,049
Blueprint one-piece 4.50–4.625 9.80 275 BPS4500100S 2,049
World two-piece 4.50–4.625 9.80 275 085012 2,667.05
Brodix two-piece AL* 4.50–4.600 9.80 142 8502000 5,038.97

*Aluminum block


Displacement Disco

The following are examples of the most common big-block Chevy bore and stroke combinations. If you have an idea for a combination that's not on our list, the formula for displacement is as follows:

Displacement = Bore x bore x stroke x 0.7854 x number of cylinders
Displacement = 4.5 x 4.5 x 4.5 x 0.7854 x 8
Displacement = 572 ci


Standard Deck Height: 9.80

Bore Stroke Cubic Inches
4.25 4.00 454
4.31 4.00 467
4.31 4.25 496
4.50 4.25 540
4.56 4.25 555
4.60 4.50 565
4.50 4.50 572
4.625 4.25 571
4.56 4.50 588
4.60 4.50 598

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21 comments
Mike Rosato
Mike Rosato

No replacement for displacement. Big blocks rule.

Pedro Perez
Pedro Perez

Camero craft worships cameros and ls. That stuff has been way overdone

Ben Earl
Ben Earl

Dan Edwards that is a Chevy big block not an LS

Howard Cooper
Howard Cooper

decided to go old school 10.5 454 in my 73 Vette

Billy Rice
Billy Rice

Nothing beats the cackle of a blown big block Chevy on alcohol.

Dan Edwards
Dan Edwards

I'd rather see an article stroking a Fiat 500 than ANOTHER LS .

Carroll Smith
Carroll Smith

any low buck LS-3 build ups coming? seeing the cylinder heads are capable of making so much h.p in stock form

Agapito Ramos
Agapito Ramos

That would be one hell of an engine, but 10k for the average joe is hard to come by.

Patty Williams
Patty Williams

My hubby built a 572 for his 55 chevy. Awesome sound & power

Car Craft