Big Mutha Thumpr Hydraulic Flat Tappet Camshaft Lift .501"/.486" Duration 295/313 RPM Range 2000-6000
InfoVehicle Info Needed
COMP CAMSPART NUMBER: 249-91-602-5

Big Mutha Thumpr Hydraulic Flat Tappet Camshaft Lift .501"/.486" Duration 295/313 RPM Range 2000-6000

$32595
ShippingShips on 09/15/2026
Lowest PriceLowest Price Guarantee

Buick Nailhead 364, 401, 425, c.i. 8 CYL. 1957-1966
  • (Classic Thumpr)
    • Big Mutha Thumpr Hydraulic Flat Tappet Camshaft
      Lift .501"/.486"
      Duration 295/313
      RPM Range 2000-6000

    • 3 Grinds To Fit All Of Your Performance Needs
    • Unique Design
    • Maximizes Sound And Mid To High RPM Power
    • Ensures Safe Piston-To-Valve Clearance
    • Proven To Generate 25+ RWHP Gains
    • Does Not Compromise Durability
    • 1 Year Limited Warranty

      Buick; 361; 401; 425; Nailhead


      Street/strip, must have head modification, 2500+ stall, very rough idle.

    Emissions Note:

    This part is only legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles or on vehicles used solely for the purposes of closed competition racing.

    CLICK THIS LINK FOR IMPORTANT CARB & EPA EMISSIONS INFORMATION ABOUT THIS PART

    Thumpr Camshafts are the hottest cams to hit the streets in more than a decade. That's because they give you the big cam sound you're looking for, without the drawbacks. Applying a camshaft design originally created for sports car endurance racing, they incorporate early exhaust valve opening, long exhaust duration, and a generous amount of intake and exhaust overlap. Best of all, Thumprs will not negatively impact power output or streetability.

    Show More Features:
    • Three unique cam designs for each application that deliver excellent horsepower gains and broad torque curve; perfect choice for muscle cars and street rods
    • Early intake valve opening and long exhaust duration create optimum overlap for powerful, hard-hitting exhaust note
    • Best with aftermarket converters and more rear gear

      Thumpr Sound ClipClick to Listen

      Camshaft & Lifter Kits are indicated by a CL in their part number and include Camshaft, Lifters, Assembly Lube, Decals, and Instructions.

      Complete Kits are indicated by a K in their part number and include Camshaft, Lifters, Timing Chain & Gears, Valve Springs, Retainers, Locks, Assembly Lube, Decals, and Instructions.

    The Comp Cams Thumpr Hydraulic Flat Tappet Cams are the perfect solution for muscle car enthusiasts and performance builders seeking that aggressive "thumpy" idle and increased engine power. Engineered to deliver impressive performance without sacrificing drivability, these camshafts are designed for vehicles that demand high-performance upgrades. Whether you're building a street rod, classic muscle car, or high-performance engine, the Thumpr camshaft is the ideal choice for anyone looking to take their ride to the next level.

    The Big Mutha Thumpr cam kit is tailored for those looking for a more aggressive, lopey idle while boosting horsepower and torque. These camshafts are specifically designed to provide maximum power and enhanced throttle response, particularly at mid-range RPMs, making them a top choice for street performance builds.

    The performance camshaft offers an ideal balance between street-friendly drivability and high-performance capability. With a unique lobe design, the Thumpr camshaft provides an unmistakable sound while increasing airflow and valve timing for more robust power delivery. These camshafts are perfect for enthusiasts who want to enhance both the sound and performance of their engine.

    If you're seeking a camshaft that makes your engine roar with authority while delivering tangible performance gains, look no further than the Comp Cams Thumpr Hydraulic Flat Tappet Cams. Upgrade your engine today and experience the difference in power, performance, and sound!

    Part TypeCamshaft
    Product LineComp Cams Thumpr Hydraulic Flat Tappet Cams
    BrandCOMP CAMS
    Package Height2.75
    Package Width3.0
    Package Length24.5
    Weight9.8 PG
    Part CategoryPerformance Parts
    Exh. Duration @ .050 In. (Deg)249
    Cam StyleHydraulic flat tappet
    Grind Number295TH7
    Exh. Duration Advertised (Deg)305
    Engine Make/SizeBuick Nailhead 264-425
    Intake Valve Lift With Factory Rocker Arm Ratio (I0.501
    Int. Duration @ .050 In. (Deg)235
    Basic Operating Rpm Range2,500-6,400
    Intake Valve Lift0.49 in (12.446 mm)
    Computer-Controlled CompatibleNo
    Int. Duration Advertised (Deg)287
    Lobe Separation (Deg)107
    Rpm Range2500-6400
    Advertised Duration295 int./313 exh.
    Exhaust Valve Lift With Factory Rocker Arm Ratio (0.486
    UsageStreet/Strip
    Valve Lift With Factory Rocker Arm Ratio0.501 int./0.486 exh.
    QuantitySold individually
    Exhaust Valve Lift0.475 in (12.065 mm)
    Advertised Intake Duration295
    Intake Duration At 050 Inch Lift243
    Exhaust Duration At 050 Inch Lift257
    Advertised Exhaust Duration313
    Lifter TypeHydraulic Flat Tappet
    Duration At 050 Inch Lift243 int./257 exh.
    Valve Springs RequiredYes
    Vendor Part Number91-602-5
    Package Qty1
    Package TypeEA
    No Questions
    No Reviews

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