Comp Cam 31-603-5 Mutha Thumpr 243/257 Camshaft Kit with Performance Lifters, True Double Roller Timing, 6.876" Push Rods - Lopey Idle Street Cam - FITS: 1969–1991 Ford 302 5.0L Engines

This complete performance kit includes the Competition Cams 31-603-5 Big Mutha’ Thumpr hydraulic flat tappet camshaft, Enginetech hydraulic lifters, a true double roller timing set, and a set of 6.876-inch performance push rods. It is designed specifically for 1969–1991 flat tappet Ford 302 hydraulic engines and will not fit Fox Body roller-cam engines or any factory roller block. This camshaft is one of the most aggressive flat tappet grinds available for classic 302 builds. It features 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 produce extremely high valve overlap, resulting in the signature Big Mutha’ Thumpr choppy idle while enhancing scavenging and improving mid-range torque output. With an operating range centered around 2,400 to 6,400 RPM, this camshaft dramatically increases throttle response, mid-range power, and the overall performance character of a flat tappet 302. The included true double roller timing set provides improved timing accuracy and reduced chain stretch compared to stock-style systems, helping maintain consistent valve events and stable performance at higher RPM. The 6.876-inch push rods ensure proper valvetrain geometry for non-roller 302 engines and add strength for the cam’s high lift and aggressive ramp profile. Matched Enginetech hydraulic lifters provide smooth operation and stable oil control, supporting the cam’s demands long-term. This kit is ideal for classic Ford street machines, hot rods, trucks, and any 1969–1991 302 build seeking a deeper, more aggressive idle, stronger mid-range power, and a full valvetrain upgrade. If you want a camshaft package that significantly transforms the performance and sound of a traditional flat tappet 302, the 31-603-5 Big Mutha’ Thumpr kit delivers outstanding results.

• THIS IS A COMPETITION CAM & ENGINETECH CAM KIT BUNDLE ASSEMBLED BY OUR EXPERT ENGINEERS TO CREATE THE HIGHEST QUALITY CAMSHAFT KIT AT AN AFFORDABLE PRICE. EVERY PART IN THIS KIT HAS A HIGH-PERFORMANCE SPEC RATING AND IS GUARANTEED TO BE OF THE HIGHEST OF QUALITY AND PERFORMANCE.
• TRUE 31-603-5 BIG MUTHA’ THUMPR CAM SPECS – Hydraulic flat tappet profile with 295/312 advertised duration, 243/257 duration at .050, .512/.497 lift, and a tight 107-degree LSA. Built for extreme Thumpr lope and hard mid-range acceleration from 2,400–6,400 RPM.
• ENGINETECH PERFORMANCE HYDRAULIC LIFTERS INCLUDED – Built for aggressive flat tappet profiles, these lifters provide reliable oil control, smooth operation, and stable valvetrain performance at higher RPM.
• TRUE DOUBLE ROLLER TIMING SET – Heavy-duty double roller chain improves cam timing accuracy, reduces stretch, increases durability, and ensures long-term performance stability compared to standard timing chains.
• INCLUDES 6.876" PERFORMANCE PUSH RODS – Strong, precision-length 6.876-inch push rods designed for SBF hydraulic flat tappet builds. Helps maintain correct valvetrain geometry and withstand higher lift and aggressive ramp rates.
• EXTREME BIG MUTHA’ THUMPR IDLE & REAL POWER GAINS – Tight 107° LSA and long exhaust duration create massive valve overlap for the signature choppy Thumpr idle while improving scavenging and mid-range torque.
• FOR 1969–1991 FLAT TAPPET FORD 302 ENGINES ONLY – Designed specifically for flat tappet 302 small block Ford engines from 1969–1991. Not for factory roller-cam engines, not for HO roller Mustangs, and not for Fox Body 5.0L roller blocks.
• COMPLETE MATCHED PERFORMANCE PACKAGE – Camshaft, lifters, timing set, and push rods are selected to work together. Eliminates compatibility guesswork and ensures proper lift support, timing accuracy, and long-term reliability.