Genuine COMP CAM 12-600-4 Thumpr 227/241 Camshaft & Enginetech High-Performance Lifters | LIFT: .479/.465" | Kit FITS Chevrolet SBC 283 327 350 400 5.7 5.7L

Stop settling for a generic idle and give your Small Block Chevy the attitude it deserves with the Competition Cams 12-600-4 Thumpr Camshaft. This isn't just a performance part; it is an auditory experience. Designed specifically for SBC 265, 283, 327, 350, and 400 engines, the Thumpr series uses cutting-edge engineering from the experts at Competition Cams to create a hard-hitting, professional race car exhaust note without the maintenance headaches of a full race setup. If you want your Camaro, Corvette, or Hot Rod to shake the pavement at a stoplight and turn every head at the car show, this is the only camshaft you should be looking at. Technically, the magic lies in the aggressive overlap designed by Competition Cams. The 12-600-4 features a Duration @ .050 of 227 intake and 241 exhaust, with a valve lift of .479”/.465”. But the real secret sauce is the tight 107-degree Lobe Separation Angle (LSA). This tight LSA is what creates that legendary, choppy, heavy-loping idle that enthusiasts dream about. Despite the wicked sound, this camshaft is engineered to operate in a street-friendly 2,000 to 5,800 RPM range. It delivers a massive flat torque curve, meaning you get that race car sound combined with genuine tire-shredding street performance. How does it feel? It feels violent in the best way possible. From the moment you turn the key, the engine will have a distinct, rhythmic "thump" that vibrates through the chassis. On the street, the throttle response is snappy and immediate. Because of the long exhaust duration, it carries power beautifully through the mid-range, making your car feel significantly faster and more aggressive. Please Note: Because of the high-performance nature of this Competition Cams profile, it works best with a 2,000+ RPM stall converter and lower rear-end gears to really let it scream. Why buy the 12-600-4? Because you are buying the industry leader in valvetrain technology. Competition Cams invented the Thumpr series to solve a specific problem: giving street guys the nasty idle they want without sacrificing vacuum or drivability to the point where the car is unuseable. You are getting premium, precision-ground durability from the most trusted name in the business. Don't guess with off-brand parts; install the genuine Thumpr, tune it up, and get ready to own the loudest, meanest-sounding car on the block.

• The Legendary "Thumpr" Sound (107 LSA): The defining feature of this cam is the ultra-tight 107-degree Lobe Separation Angle. Why Buy It: This specific geometry creates early intake valve opening and long exhaust overlap, generating that highly desirable, rough, choppy, race-car idle that sounds far more aggressive than the cam actually drives.
• THIS LISTING WILL INCLUDE:
• 1)AUTHENTIC COMP CAM 12-600-4 THUMPR 227/241 HYDRAULIC CAMSHAFT - Hydraulic Flat Cam for Chevrolet Small Block 262-400. High performance street, stock converter ok, best with 2000+ converter and gears. Choppy/thumping idle.
• 16) ENGINETECH HIGH-PERFORMANCE HYDRAULIC LIFTERS
• Optimized Street Performance Specs: With a Duration @ .050 of 227 Int / 241 Exh, this cam places the power right where you play—between 2,000 and 5,800 RPM. Why Buy It: It gives you a massive boost in mid-range horsepower and torque, making it perfect for street rods and muscle cars that need to back up their bark with bite.
• High-Velocity Lift Profile (.479”/.465”): The lift is calculated at .479” Intake and .465” Exhaust. Why Buy It: This profile maximizes cylinder filling on stock or modified cylinder heads without being so aggressive that it destroys your valvetrain longevity, striking the perfect balance between power and reliability.
• Engineered by Competition Cams for SBC: Designed for 1955-1998 Small Block Chevys (262-400ci) using flat tappet lifters. Why Buy It: It allows you to achieve the sound of a high-compression drag car on a standard street engine. Tech Tip: For the best experience, we recommend pairing this with a 2000+ stall converter and headers to amplify that signature sound.