This is a Chevrolet 350 V8 that was built by industry icon Nat Chiavettone into a fire-breathing 357 cubic inch crate engine, capable of 501 bhp on high-octane pump gas.
The engine now has Airflow Research 190cc aluminum cylinder heads, forged AutoTec pistons, 6″ H-beam forged connecting rods, a steel crankshaft, a Competition Cams hydraulic roller camshaft, an aluminum Edelbrock intake manifold, and a Holley 750 CFM Quick-Fuel carburetor.
Nat Chiavettone seen here supervising a dyno run at his famous workshop in Swansea, Massachusetts. Image courtesy of Nat’s Racing Engines.
New England Legend Nat Chiavettone
Nat Chiavettone has been one of the most respected engine builders in New England racing scene for decades, though you’d never know it from walking into his shop. Operating out of Swansea, Massachusetts, under the business name Nat Chiavettone Associates Inc. (better known as Nat’s Racing Engines), his workshop at 702 Warren Avenue was famously devoid of trophies, plaques, or any self-congratulation — just an immaculate floor and rows of gleaming machinery ready to make noise (and horsepower).
Chiavettone’s client list reads like a cross-section of New England short-track racing. He built engines for nearly every category of racecar in the region, from Modifieds, Late Models, Sportsman cars, and trucks at the local level – as well as for teams competing in the NASCAR Modified Tour, the Busch North Series, and the old Pro Truck series.
Beyond the oval tracks, his work powered countless drag racers, road racers, and street-legal hot rods. He was particularly well known around Seekonk Speedway, where his engines were a fixture in the pits for years. Among his documented builds was a Chevrolet 350 cubic inch crate engine producing over 400 bhp – built for the BGB Racing Team’s “Red Devil” Modified in 2005.
His workshop also served as a destination for dyno testing engines outside the racing world, an original LS6 engine from a 1970 Chevrolet Chevelle SS and a numbers-matching engine from a 1968 Pontiac Firebird 400 convertible were both brought to Nat Chiavettone Associates Inc. to be put on the dyno, and a GM Performance 572 cubic inch big block V8 producing over 620 bhp was tested there as well.
Chiavettone turned 90 this year, but he can still be found roaming the pits on race day, supporting his customers and chasing every last fraction of horsepower from their engines. He’s known for being a genuine, humble figure who cares deeply about the sport, its competitors, and its future.
Chiavettone’s client list reads like a cross-section of New England short-track racing. He built engines for nearly every category of racecar in the region, from Modifieds, Late Models, Sportsman cars, and trucks at the local level – as well as for teams competing in the NASCAR Modified Tour, the Busch North Series, and the old Pro Truck series. Image courtesy of Nat’s Racing Engines.
In 2022, Chiavettone was inducted into the New England Auto Racers Hall of Fame as part of the Class of 2022, recognized in the Engine Builder category, joining a tradition of builder-inductees that includes Rollie Lindblad (Class of 2009) and Joe Fontana (Class of 2015).
The Chevrolet 357 V8 Crate Engine Shown Here
This 350 Chevrolet V8 crate engine was built by Nat Chiavettone in 2026 and has been bored 0.040″ over, bringing its displacement up to 356.7ci. It was developed to run on high-octane pump fuel with a 10:1 compression ratio, and was dyno tested in March of 2026 at Chiavettone’s workshop, where it produced 501 hp and 464 lb ft of torque.
The dyno sheet and cam card are included with the sale, along with a video of the engine being run.
The rotating assembly is built around a Chevrolet steel crankshaft supported by four-bolt main bearing caps and Clevite rod and main bearings, with a Fluidampr harmonic balancer managing torsional vibration.
The pistons are forged AutoTec units fitted with RaceTec piston rings, connected to the crank via 6″ H-beam forged connecting rods. The valvetrain is head up by a Competition Cams hydraulic roller camshaft riding on Dura-Bond cam bearings, with GM hydraulic roller lifters, Crower Cams 1.6/1.5 rocker arms, and beehive valve springs. Lubrication is handled via a Champ 7-quart oil pan and a WIX Racing oil filter.
Up top, the engine is fitted with a pair of Airflow Research 190cc aluminum cylinder heads and an aluminum Edelbrock intake manifold, topped by a Holley 750 CFM Quick-Fuel carburetor fed through braided fuel lines and a Carter high-performance fuel pump.
This 350 Chevrolet V8 crate engine was built by Nat Chiavettone in 2026 and has been bored 0.040″ over, bringing its displacement up to 356.7ci. It was developed to run on high-octane pump fuel with a 10:1 compression ratio, and was dyno tested in March of 2026 at Chiavettone’s workshop, where it produced 501 hp and 464 lb ft of torque.
Ignition is managed by an MSD Street Fire HEI distributor, with new Autolite spark plugs recently installed and the timing freshly set. Cosmetic and ancillary details include aluminum valve covers, a chrome roller timing cover, Billet Specialties breather caps, and a Billet Specialties water neck with a 180º thermostat.
The engine is now being offered at no reserve out of Seekonk, Massachusetts, and it comes mounted on a custom engine stand with wheels. If you’d like to read more about it or place a bid you can visit the listing here.
Images courtesy of Bring a Trailer
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