Comp Cam 31-603-5 Thumpr 243/257 Camshaft and High Performance Hydraulic Lifters Kit – Rough Idle Street Cam – 295/312 Duration, .512/.497 Lift, 107° LSA – FITS Ford 289 302 5.0L SBF Engines

Description

This performance kit features the Competition Cams 31-603-5 Big Mutha’ Thumpr hydraulic flat tappet camshaft paired with Enginetech high-performance hydraulic lifters to deliver a powerful upgrade for Ford 221-302 small block engines. Designed for builders who want a dramatic improvement in sound, throttle response and mid-range torque, this camshaft is one of the most aggressive grinds available for flat tappet SBF applications.

The 31-603-5 Big Mutha Thumpr camshaft is engineered with 295 and 312 degrees advertised duration, 243 and 257 degrees duration at .050, .512 and .497 inches of lift, and a tight 107 degree lobe separation angle. These specifications create extremely high valve overlap, which produces the loud, choppy Thumpr idle while improving exhaust scavenging and airflow through the cylinders. The extended duration and higher lift move the powerband upward, giving the engine a much harder-hitting mid-range and a noticeably stronger pull during acceleration. This camshaft is designed for engines that operate primarily in the mid-to-upper RPM range and benefits significantly from compression increases, aftermarket intake systems, tuned carburetion or EFI, and free-flowing exhaust systems.

With an operating range centered around 2,400 to 6,400 RPM, the 31-603-5 camshaft offers more aggressive throttle response and stronger top-end performance compared to mild or stock camshafts. The tight 107 LSA not only enhances the exhaust note but also increases cylinder pressure at the right points in the RPM band, helping the engine produce more torque where street and street/strip builds need it most. This camshaft creates a noticeable performance difference that drivers can feel immediately.

Included Enginetech hydraulic lifters are engineered to match aggressive flat tappet cam profiles, supporting stable lifter action and proper oil control even under the higher loads created by this lift and duration. These lifters help ensure smooth valvetrain operation, reliable break-in, long-term stability, and consistent performance over time.

This kit is an ideal choice for Ford 221, 260, 289 and 302 flat tappet engines used in classic muscle cars, street rods, hot rod projects or street/strip builds where sound and performance are priorities. If you want a camshaft that dramatically changes the tone, character and acceleration of your Ford small block engine, the Comp 31-603-5 Big Mutha Thumpr camshaft with Enginetech performance hydraulic lifters is one of the most impactful and reliable upgrades available.

Manufacturer: COMP CAMS / ENGINETECH
Model: SBF THUMPR 243/257
Included components: 1-CAMSHAFT 16-LIFTERS
Warranty: 2 YEAR MANUFACTURER WARRANTY