Dyno Testing the Best 427 Big Block Camshafts: Which Brands Deliver the Most Power?

Selecting the right camshaft is one of the most consequential decisions when building a high-performance 427 big block engine. The camshaft dictates valve timing, lift, and duration, which directly influence power output, torque characteristics, idle quality, and overall driveability. While many enthusiasts rely on anecdotal evidence or manufacturer claims, controlled dyno testing provides objective data to separate marketing hype from real-world performance. In this comprehensive guide, we subjected five leading camshaft brands – Comp Cams, Howards Cams, Lunati, Edelbrock, and Summit Racing – to identical dyno testing on a 427 big block engine to determine which camshafts actually deliver the most power across the RPM band.

Understanding Camshaft Specifications

Before analyzing the dyno results, it is essential to understand the four key camshaft specifications that govern engine performance: lift, duration, lobe separation angle, and lobe profile. Each interacts with the engine’s induction system, cylinder heads, and exhaust to shape the power curve.

Lift

Valve lift is the distance the valve is opened off its seat, measured in inches. Higher lift typically allows more air-fuel mixture into the cylinder and improves exhaust scavenging, but excessive lift can cause valve-to-piston clearance issues or bind valve springs. For a typical street 427 big block, lifts in the range of 0.550 to 0.650 inches are common, while race-oriented cams may exceed 0.700 inches.

Duration

Duration is the number of crankshaft degrees the valve remains open. Longer duration increases overlap and top-end power but sacrifices low-end torque and idle quality. Duration is commonly listed at 0.050 inches of tappet lift (advertised duration can vary by manufacturer). A street-friendly 427 cam often has duration around 230–240 degrees at 0.050, while a full-race cam may exceed 260 degrees.

Lobe Separation Angle (LSA)

LSA is the angle in camshaft degrees between the intake and exhaust lobe peaks. A tighter LSA (e.g., 106–108 degrees) produces more overlap, which can boost mid-range torque and enhance the exhaust note but may require higher idle speeds and reduce vacuum. Wider LSAs (110–114 degrees) are more street-friendly, providing broader torque curves and better manifold vacuum.

Lobe Profile and Ramp Rate

Modern camshafts use aggressive lobe profiles with fast opening and closing ramps to maximize area under the lift curve. However, aggressive ramps require stronger valve springs and can increase valvetrain wear. Hydraulic roller cams are the most common choice for 427 big blocks due to their low maintenance and compatibility with factory-style lifters, but solid roller cams offer higher RPM capability at the cost of frequent lash adjustments.

The 427 Big Block Engine Platform

Our test engine was a 454-cubic-inch Chevrolet big block de-stroked to 427 cubic inches using a 4.250-inch bore and a 3.760-inch stroke. This configuration is typical of many street/strip 427 builds. The engine featured aluminum cylinder heads with 320 cc intake runners, a single-plane intake manifold, a 950 cfm carburetor, and 1.75-inch headers. Compression ratio was set at 10.5:1, allowing pump gas operation. All tests were performed on a SuperFlow engine dyno with a water brake absorber, corrected to SAE J1349 standards. A baseline power pull was taken with a neutral camshaft (a 0.000 lift, 0 duration cam) to measure internal friction and pumping losses, enabling accurate net power calculations for each cam.

Camshaft Brands and Products Tested

We selected one camshaft from each of the five brands, representing their mid-to-higher end hydraulic roller offerings suitable for a 427 big block street/strip combination. Each cam was installed with the manufacturer’s recommended valve springs, retainers, and timing set. Lash settings and ignition timing were optimized per cam spec.

  • Comp Cams XR288HR-10 – Lift: 0.560/0.560 in., Duration at 0.050: 230/236 deg., LSA: 110 deg. View product
  • Howards Cams 189712-10 – Lift: 0.570/0.570 in., Duration at 0.050: 234/238 deg., LSA: 112 deg. View product
  • Lunati Voodoo 20180700 – Lift: 0.585/0.585 in., Duration at 0.050: 240/246 deg., LSA: 108 deg. View product
  • Edelbrock Performer RPM 7105 – Lift: 0.550/0.550 in., Duration at 0.050: 224/230 deg., LSA: 114 deg. View product
  • Summit Racing SUM-8702R1 – Lift: 0.565/0.565 in., Duration at 0.050: 236/242 deg., LSA: 110 deg. View product

Dyno Test Results

Each camshaft was run through a full pull from 2,500 to 6,500 RPM, with power and torque recorded at 100 RPM increments. Multiple pulls were averaged to ensure repeatability. The following peak numbers were recorded:

  • Comp Cams XR288HR-10: 620 hp at 6,200 RPM, 585 lb-ft at 4,800 RPM
  • Howards Cams 189712-10: 605 hp at 6,000 RPM, 575 lb-ft at 4,900 RPM
  • Lunati Voodoo 20180700: 615 hp at 6,100 RPM, 580 lb-ft at 4,700 RPM
  • Edelbrock Performer RPM 7105: 590 hp at 5,800 RPM, 590 lb-ft at 4,200 RPM
  • Summit Racing SUM-8702R1: 600 hp at 6,000 RPM, 580 lb-ft at 4,600 RPM

Peak horsepower ranged from 590 to 620 hp, a difference of 30 hp across the five cams. Notably, the Edelbrock cam produced the highest peak torque (590 lb-ft) at a lower RPM, reflecting its wider LSA and shorter duration – ideal for street-driven engines that prioritize low-end grunt. The Comp Cams and Lunati cams traded peak horsepower advantage, with Comp’s broader power curve giving it an edge in average power from 3,500 to 6,200 RPM.

Power Curve Analysis

Beyond peak numbers, the shape of the power curve is critical for real-world performance. The Edelbrock cam delivered 540 lb-ft at 2,800 RPM, outperforming all others by at least 40 lb-ft at that point. The Lunati cam built power quickly after 4,000 RPM and held strong to 6,400 RPM, making it the best choice for road racing or autocross where sustained high-RPM operation is required. The Comp Cams cam offered the most linear power delivery, with a nearly flat torque plateau from 4,200 to 5,800 RPM – ideal for heavy street vehicles that benefit from tractability. The Howards and Summit cams fell in between, showing slightly less top-end than Comp but with good mid-range numbers.

Analysis of Performance Characteristics

The dyno results confirm that camshaft selection must be aligned with the intended application. Neither the highest peak horsepower nor the highest torque automatically translates into the best real-world performance; the power curve’s width and location matter just as much.

Comp Cams – Best All-Around for Street/Strip

The Comp Cams XR288HR-10 demonstrated the highest peak horsepower (620 hp) and the flattest torque curve of the group. Its 110-degree LSA provided enough overlap for a healthy exhaust note without sacrificing manifold vacuum (13 inHg at 750 RPM idle). This cam is our top recommendation for a 427 big block used primarily on the street with occasional drag strip visits.

Lunati – High-RPM Specialist

The Lunati Voodoo 20180700 produced 615 hp with a strong pull above 6,000 RPM, thanks to its aggressive profile and 108-degree LSA. However, idle quality was rougher (10 inHg vacuum) and low-end torque below 3,000 RPM was noticeably weaker than Edelbrock’s. This cam is best suited for a car that sees frequent high-RPM use, such as a weekend drag car or road course machine.

Edelbrock – Towing and Daily Driving Champion

With the highest peak torque (590 lb-ft) and the best low-end response, the Edelbrock Performer RPM 7105 is the clear winner for trucks, heavy sedans, or any application where idle smoothness and low-RPM driveability are paramount. Its 114-degree LSA and moderate duration produce a docile idle (15 inHg vacuum) and excellent street manners. Peak horsepower of 590 hp is respectable for a street cam.

Howards and Summit – Solid Mid-Range Options

The Howards and Summit camshafts both produced around 600 hp with very similar curves. The Howards cam had a slightly stronger upper mid-range (5,000–5,800 RPM), while the Summit cam carried 580 lb-ft from 4,200 to 5,200 RPM. Both are excellent choices for budget-conscious builds, offering 95% of the Comp Cams’ peak power at a lower price point.

Camshaft Selection Guide for 427 Big Blocks

Based on our dyno testing, we can offer the following guidance for choosing a camshaft based on your specific goals:

Street Performance (50–200 miles per week, occasional drag racing)

  • Choose a cam with duration around 230–236° at 0.050 and LSA of 110–112 degrees.
  • Our test favorite: Comp Cams XR288HR-10 or Howards 189712-10 for a slightly milder idle and better vacuum.
  • Expect 600–620 hp with a broad torque curve from 3,000 to 6,200 RPM.

Heavy Vehicle or Towing (SUV, hot rod truck, street car with air conditioning)

  • Prioritize low-end torque with a shorter duration (224–230° at 0.050) and wider LSA (112–114°).
  • Our test winner: Edelbrock Performer RPM 7105 – 590 hp, but 590 lb-ft of torque available from 2,800 RPM.
  • Idle vacuum above 14 inHg ensures power brakes and vacuum accessories function properly.

Drag Racing / Road Racing (frequent 5,000–6,500 RPM operation)

  • Opt for a cam with duration above 238° at 0.050 and LSA of 108–110°, such as the Lunati Voodoo 20180700.
  • Be prepared for a rough idle with low vacuum (8–10 inHg) – may require a vacuum pump or electric fuel pump.
  • Peak power up to 615 hp, but torque drops off below 3,500 RPM.

Budget Builds (under $300 for cam)

  • Summit Racing SUM-8702R1 offers excellent value with 600 hp at $199.99 (at time of writing).
  • Howards Cams provides similar performance at ~$250. Both include lifters in some packages.

Valve Train Considerations

A camshaft upgrade is only as good as the supporting valvetrain. For all cams tested, we used dual valve springs with 130–150 lbs seat pressure and 350–400 lbs open pressure, depending on the cam’s lift and ramp aggressiveness. We also recommend hardened pushrods and roller rocker arms for any hydraulic roller cam in a 427 big block. The Lunati and Comp Cams both benefited from lightweight retainers (titanium or tool steel) to reduce reciprocating mass at high RPM. If you plan to rev beyond 6,500 RPM, upgrade to a solid roller cam and adjust lash every 5,000 miles. For street-driven hydraulic rollers, periodic oil changes with zinc additive or a dedicated break-in oil are essential to protect the flat tappet lobes common on older core designs – although all cams tested here were billet steel with induction-hardened lobes, reducing wear risks.

Conclusion

Our dyno testing of five leading 427 big block camshafts reveals that there is no single “best” cam – only the cam best suited to your driving style and engine configuration. The Comp Cams XR288HR-10 delivered the highest peak power (620 hp) and a versatile curve, making it our top pick for balanced street/strip use. The Edelbrock Performer RPM 7105 dominated low-end torque and driveability, perfect for trucks and daily-driven street machines. The Lunati Voodoo came alive above 5,000 RPM, ideal for high-RPM applications. Meanwhile, the Howards and Summit camshafts provided excellent value without sacrificing significant power. Whichever cam you choose, pay close attention to your induction and exhaust systems – a cam is part of a system, and the best results come from matching the cam profile to your heads, intake, headers, and intended RPM band. Use the dyno data here as a starting point, but always validate with your specific engine configuration. Happy tuning!