ATK HP33C High Performance GM 383 Vortec Stroker — 390 HP Stage 3 Long Block Crate Engine

390 horsepower. 460 lb-ft of stump-pulling torque. Dyno-proven and crated for Europe. The ATK HP33C is the 383 stroker engine that hot rodders have trusted for decades — a Chevy small block stroked to 6.3L / 383 cubic inches, topped with Dart Vortec cast-iron heads, and delivered as a zero-hour Stage 3 long block. Scat nodular-iron crank, moly rings, double-roller timing, hydraulic roller cam, 9.5:1 compression on 92-octane pump gas — a street-friendly package with a muscle car attitude. Crated and shipped fast across Europe from NH Race Engine.

Why Choose the ATK HP33C 383 Stroker Engine?

Anyone can bolt together a stroker kit — ATK dyno-tests every engine before it leaves. The HP33C is the Stage 3 evolution of ATK’s most popular small-block build: a 1996–2000 OE roller block, four-bolt mains and a 1-piece rear seal for modern sealing, then a Scat 3.750″ stroke crank and 4.040″ bore that wake the old 350 architecture up completely. The result is 390 HP and 460 TQ — more torque than most big blocks of the muscle era, on pump gas, with hydraulic-roller reliability and daily-driver manners.

The Vortec-headed top end is the secret sauce: Dart’s 165cc intake-runner heads with 67cc chambers and 2.02/1.60 valves flow like race heads but keep velocity up for street torque. A mild hydraulic roller cam means no valve adjustments, no flat-tappet break-in drama, and a lopey-but-civil idle that won’t annoy the neighbors. This is the engine for the builder who wants real power without a race-shop budget or race-gas bills.

383 Stroker Engine Key Features & Benefits

• 390 HP / 460 TQ — Dyno-Proven: Every engine is run and certified on ATK’s dyno before crating. No guesswork, no inflated catalog numbers.
• Scat Stroker Rotating Assembly: Nodular-iron 3.750″ stroke crank with 4.040″ bore = true 383 cubic inches. Moly rings for sealing and longevity.
• Dart Vortec Cylinder Heads: Cast-iron 67cc/165cc runners, 2.02/1.60 stainless valves — race-bred flow with street-friendly velocity.
• Hydraulic Roller Cam: Modern roller reliability, broad torque curve, no periodic valve-lash adjustment.
• 4-Bolt Main OE Roller Block: 1996–2000 GM roller-cam block with 1-piece rear main seal — the strongest factory architecture for stroker power.
• Double-Roller Timing Chain: Bulletproof timing for high-RPM stroker duty.
• 9.5:1 Compression on 92 Octane: Real street power without race gas — European pump fuel compatible.
• Stage 3 Blueprint: Balanced, assembled and torque-striped to ATK’s performance spec by certified builders.

383 Stroker Engine Recommended Applications

The HP33C is a performance long block for hot rods, muscle cars and street machines — not a factory-fitment engine:

• Classic Muscle: Chevelle, Camaro, Nova, El Camino, Impala — carbureted or EFI conversions
• Street Rods & Customs: ’32 Fords, Tri-Fives, gassers and pro-street builds needing real torque
• C10 & Square-Body Trucks: The classic pickup upgrade — Vortec-headed 383 torque transforms a hauler
• Restomods: Pair with modern EFI (Holley Sniper, FiTech) for classic looks with new-engine drivability
• Marine & Off-Road: Torque-hungry applications where reliability matters (verify marine suitability with our team)

Notes: The HP33C is a long block — intake manifold, carburetor/EFI, distributor, oil pan, valve covers, timing cover, water pump, balancer, flywheel/flexplate and exhaust headers are required to complete. See companion products below. Recommended maximum sustained RPM: 5,800.

Technical Specifications

What’s Included vs. What You Need

HP33 vs HP33C vs HP94C — Which ATK 383 Is Yours?

Unsure which 383 fits your build and budget? Send us your vehicle, transmission and goals — we’ll spec the right package.

Frequently Asked Questions

What carburetor do you recommend for the HP33C?

A 650–750 CFM 4-barrel (Holley, Edelbrock or Quick Fuel) matches the Dart Vortec heads perfectly. For EFI builds, a Holley Sniper or FiTech system on a Vortec-pattern intake gives modern drivability with the same 390 HP.

Can I run this 383 stroker engine on European pump fuel?

Yes — 9.5:1 compression on 92-octane (RON ~98–99) is well within European premium pump fuel. No additives or race gas needed.

What transmission pairs best with the HP33C?

The 460 TQ calls for a stout box: a built TH350/TH400, 700R4/4L60E (upgraded), TKO or T56 manual depending on your build. Tell us your setup and we’ll advise on converter stall and gearing — 3.23–3.55 rear gears suit the torque curve.

What’s the break-in procedure for a high-performance crate engine?

ATK requires a specific break-in: vary RPM between 2,000–2,500 for the first 20 minutes with immediate load cycles, no extended idling, and an oil/filter change at 500 miles using quality conventional oil with zinc (ZDDP). We supply break-in oil and detailed instructions with every HP engine.

Is the HP33C suitable for marine or truck towing use?

The HP line is tuned for performance street duty. For sustained marine or heavy-towing applications, ATK’s dedicated marine and truck lines use different cams and compression — contact our team and we’ll point you to the right engine (see our marine engine range).

Recommended Companion Products

• Vortec-pattern intake manifolds — carb & EFI
• 650–750 CFM carburetors
• EFI conversion kits — Holley Sniper, FiTech
• HEI & performance distributors
• Headers & exhaust for small block Chevy
• Flywheels & flexplates — SBC balance
• ZDDP break-in oil & assembly lubricant
• Performance transmissions & converters
• VEGE DCH4 — Vortec 350 for factory-fit builds
• All crate engines — remanufactured & high performance

Shipping Your 383 Stroker Engine Across Europe

NH Race Engine ships ATK 383 stroker engine long blocks across Europe from our EU warehouse. High-performance engines ship crated on a pallet via insured freight carrier with full tracking — dyno sheets and build documentation included with every HP-series engine.

Estimated delivery: Netherlands 3–5 business days | Germany, Belgium, France 5–7 business days | Rest of EU 7–10 business days

Liftgate delivery available on request. Contact us for a freight quote to your address or workshop.

Order Your ATK HP33C 383 Stroker Engine Today

Stop browsing forums and start driving. The ATK HP33C 383 stroker engine delivers 390 dyno-proven horsepower and 460 lb-ft of torque in a street-friendly, pump-gas package — built by America’s largest crate engine specialist and crated for delivery to your European build.

Contact our technical team with your vehicle and build goals for a complete package quote, or click “Add to Cart” now to secure yours.

Call [PHONE] or email [EMAIL] for expert advice on high-performance crate engines.

SKU: ATK-HP33C | MPN: HP33C | Brand: ATK High Performance Engines | Category: High Performance Crate Engines / Stroker Long Blocks