What Is the COMP Cams 383 Stroker Kit?

The COMP Cams 383 Stroker Kit is a complete rotating assembly engineered to transform a standard 350 cubic inch small-block Chevy (SBC) into a 383 stroker. By increasing the stroke from 3.48 inches to 3.75 inches, the kit bumps displacement by 33 cubic inches, yielding significant gains in both horsepower and torque. The kit is sold as a matched set of components that work together to handle higher cylinder pressures and RPMs, making it a popular choice for street performance, hot rods, and even mild racing applications.

Unlike buying individual parts from different manufacturers, a pre-balanced kit from COMP Cams eliminates guesswork around clearances, reciprocating weight, and dynamic balance. This is critical for achieving smooth operation at high RPM and avoiding premature bearing or crank failure.

Key Components Included

The kit is typically sold in two configurations: a base kit and a premium (forged) kit. The premium version includes:

  • Forged 4340 steel crankshaft with a 3.75-inch stroke, indexed and ground with a 350 main journal size. COMP Cams uses a proprietary heat-treat process to improve fatigue strength.
  • Forged 4340 H-beam connecting rods with ARP 7/16-inch cap screw bolts and a 6.0-inch center-to-center length. These rods are lighter and stronger than stock cast or powdered-metal rods.
  • Forged pistons from either Wiseco or JE Pistons (depending on the kit revision), featuring a 1.125-inch compression height, 1.5mm/1.5mm/3.0mm ring pack, and a 4.030-inch standard bore. Pistons are offered in several dome/dish volumes to achieve desired compression ratios.
  • Low-friction piston rings (typically moly faced top ring, ductile iron second ring).
  • Camshaft – the kit includes a specific COMP Cams Xtreme Energy cam (e.g., part 08-467-8) designed for 383 stroker characteristics, with 224/230 degrees of duration at 0.050-inch lift and a 110-degree lobe separation angle. Lift is 0.507/0.510 inch with 1.6 ratio rockers.
  • Timing chain set – a double-roller timing chain (COMP Cams part 3103) is included to withstand the greater cam torque.
  • Main and rod bearings – Clevite H-series tri-metal bearings, pre-gapped for the stroker application.
  • Camshaft bearings (often Dura-Bond or Clevite).
  • Piston pins and locks.

The base kit uses a cast steel crankshaft and hypereutectic pistons, which are adequate for street use up to about 500 hp. The forged kit is recommended for builds targeting 500+ hp, forced induction, or sustained high-RPM operation.

Owner Reviews and Real-World Experiences

Hundreds of owners have documented their builds on forums such as LS1Tech, ThirdGen.org, and Speed-Talk. While the kit draws mostly positive feedback, several patterns emerge across reviews.

Power Gains and Dyno Results

The most frequently cited benefit is immediate, noticeable power. With a proper tune and a decent cylinder head (e.g., AFR 195cc or Edelbrock E-Tec 170cc), owners report rear-wheel dyno numbers ranging from 350 to 420 horsepower for the forged kit, with torque peaking in the 420–470 lb-ft range. One well-documented build on LS1Tech showed 391 hp and 445 lb-ft at the wheels through a TH350 and 3.73 gears, using a mild XR276HR cam and CNC-ported heads. Many owners note that the torque curve is exceptionally flat, with over 400 lb-ft available from 2500 to 5500 RPM.

A small percentage of users who paired the kit with aggressive cylinder heads (e.g., 200+ cc intake runners) and a high-lift roller cam (0.600+ inches) have reported north of 500 crank horsepower. It's important to note that the included Xtreme Energy cam is a good all-arounder, but builders chasing maximum numbers often swap to a different cam profile – something many reviewers confirm.

Installation Difficulty and Tips

The kit is designed for DIY installation with standard hand tools and an engine stand, but several owners caution about clearancing. The 3.75-inch stroke requires minor grinding on the block (main bulkhead and lower cylinder wall reliefs) to clear the rod bolt at the bottom of the stroke. COMP Cams includes a set of clearancing instructions, but first-time builders should read thoroughly. One user on The H.A.M.B. noted that he spent two extra hours filing the block webbing to achieve 0.050-inch clearance on all rods. On a few blocks (especially 2-bolt mains), owners recommend using a stud girdle or upgrading to ARP main studs, as the additional stroke adds stress to the lower end.

Another common piece of advice: always measure piston-to-deck height and adjust head gasket thickness to achieve the intended static compression ratio. The kit ships with commonly used compression heights, but block deck heights vary after years of wear or previous machining. Static compression should be between 9.5:1 and 10.5:1 for pump gas.

Driveability and Sound

Reviewers almost universally praise the idle quality and exhaust note. The Xtreme Energy cam provides a distinct "choppy" idle that sounds aggressive without being obnoxious. Engine vacuum at idle typically stays above 12 inches of Mercury, which is enough to operate power brakes and a traditional automatic transmission modulator. Owners report good low-RPM response – the 383 stroker pulls smoothly from 1500 RPM, making it pleasant for daily driving. However, some users running the kit with a steep rear gear (4.10 or lower) note that the combination is very "peppy" in first and second gear, requiring careful throttle modulation.

Reliability and Maintenance

Reliability is consistently rated high. Many owners have logged 30,000–50,000 miles on forged kits with no internal failures, using a properly tuned carburetor or EFI system. The key to longevity appears to be proper piston-to-wall clearance (0.0035–0.0045 inch for forged pistons) and meticulous assembly with high-quality assembly lube. A few isolated cases of rod bolt failures were linked to overtightening – COMP Cams uses ARP bolts that require a specific torque-angle procedure. Following the included torque spec sheet is critical.

One recurring minor complaint: the included main bearings sometimes require an oil clearance check and occasional replacement with a different size (e.g., Clevite p/n 4M4468). While not a design flaw, it underscores that every build benefits from a precision assembly.

Performance Data Analysis

Beneath the anecdotal praise, solid data confirms the kit’s capability. COMP Cams and independent builders have published benchmark results.

Horsepower and Torque Curves

Using the supplied cam, a typical 383 with 9.8:1 compression, AFR 195 heads, an Edelbrock Performer RPM intake, and a 750cfm carb delivers approximately 420 hp at 5800 RPM and 460 lb-ft of torque at 4200 RPM. The torque curve is extraordinarily flat: from 2500 to 5500 RPM, torque stays above 400 lb-ft. This wide "torque plateau" is the signature of a well-designed stroker, and the COMP Cams kit excels here. Even with the base cast version, dyno tests show about 400 hp and 440 lb-ft with similar induction.

When compared to a stock 350 (approximately 300 hp and 330 lb-ft), the 383 kit offers a 100+ hp gain and 100+ lb-ft gain – an impressive return for a relatively simple rotating assembly swap.

RPM Range and Volumetric Efficiency

The standard 3.75-inch stroke length, combined with the 6.0-inch rod, yields a rod-to-stroke ratio of 1.6:1. This is favorable for reducing side loading on the cylinder walls and improving high-RPM breathing. The kit’s components are balanced to a fine tolerance (typically within 2 grams). Owners report revving to 6200 RPM confidently with the forged crank; the cast variant is usually limited to 5800 RPM. Volumetric efficiency peaks around 95% at the torque peak, which is very good for a street V8.

Comparison with Other Stroker Kits

Several competitors offer 383 kits, including Eagle Specialty Products, Scat Enterprises, and Summit Racing’s in-house brand. A direct comparison reveals strengths and weaknesses for each.

Eagle vs. COMP Cams vs. Scat

Eagle’s 383 forged rotating assembly (part number ESA-383) is a common budget alternative. It uses an Eagle cast or forged crank and Eagle H-beam rods, with SRP pistons. The Eagle kit is typically $300–$400 less than COMP Cams, but reviewers note that the included camshaft – if any – is often a generic grind. The Eagle kit is a good choice if you already have a cam profile in mind. Scat’s 383 kit uses 4340 forged parts and is priced similarly to COMP Cams, but it does not include a timing set or bearings in many configurations. Owners report that Scat’s balancing is good, but less consistent out of the box.

COMP Cams stands out for the completeness of the kit and the specific cam lobe design. The cam is dyno-matched to the rotating assembly, which removes guesswork. Customer support by phone and email is better than Eagle or Scat, according to multiple forum threads. On the other hand, Eagle and Scat allow you to select any compression ratio or rod length without paying a premium for custom parts – a flexibility that advanced builders value.

Cost-Benefit Analysis

At current pricing (approximately $1,500–$1,900 for the forged kit and $1,000–$1,300 for the base kit), the COMP Cams 383 stroker kit represents a solid value when you factor in the included cam and timing set. A comparable custom combination from individual parts (crank, rods, pistons, rings, bearings, cam, timing set) can easily exceed $2,200. The base kit, using hypereutectic pistons and a cast crank, is ideal for street cars with moderate power goals (up to 450 hp) on a tight budget.

Tuning and Supporting Modifications

To realize the full potential of the COMP Cams 383 stroker kit, supporting modifications are essential. The kit alone will not make big power if the cylinder heads, intake, and exhaust are stock. Recommendations include:

  • Cylinder heads: Aftermarket aluminum heads with 180–200cc intake runners (e.g., AFR 195 Eliminator or Edelbrock E-Street).
  • Intake manifold: A dual-plane like Edelbrock Performer RPM or a single-plane for high-RPM focus.
  • Carburetor/EFI: 650–750 cfm for most street applications; 850 cfm for high-RPM builds. Fuel injection (e.g., Holley Sniper) can improve drivability.
  • Exhaust: Full-length headers with 1.625- to 1.75-inch primary tubes and a 3-inch exhaust system.
  • Ignition: Upgrade to a high-energy distributor (HEI or MSD) with adjustable advance curve.
  • Oil system: A high-volume oil pump and a deeper oil pan are recommended due to the increased crankcase windage from the longer stroke.

Tuning the carburetor or EFI for the larger displacement and the specific cam profile is mandatory. Many owners recommend a professional dyno tune session to safely push timing and air-fuel ratios. The kit's compression ratio and cam timing are forgiving, but an overly lean mixture or excessive timing can cause detonation, especially with 87 octane fuel – stick with 93 or higher with the forged kit.

Conclusion and Recommendations

The COMP Cams 383 Stroker Kit is a well-engineered, comprehensive package that delivers exactly what it promises: a noticeable increase in horsepower and torque, excellent drivability, and long-term reliability. Owner reviews consistently highlight the seamless integration of components and the immediate performance gain. The included camshaft, while not the hottest available, is a smart choice that balances power with street manners.

Who should buy this kit?

  • First-time builders who want a proven, balanced combo out of the box.
  • Owners building a street-driven small-block Chevy targeting 400–500 hp.
  • Enthusiasts who appreciate COMP Cams’ technical support.

Who might look elsewhere?

  • Budget-minded builders who already have a cam and timing set and just need the bottom end.
  • Racers who want maximum power and plan to swap in a custom roller cam and dedicated rods/pistons.

Before purchasing, verify your block's deck height and main bearing bore condition. Order the kit with the correct piston option (flat-top, dome, or dish) to match your desired compression. With proper assembly and tuning, the COMP Cams 383 Stroker Kit will transform your classic Chevy into a street-dominating machine that runs strong for tens of thousands of miles.