COMP CAM 12-601-4 Mutha Thumpr 235/249 Engine Rebuild Overhaul Kit | 10:1 Flat Top Pistons | Double Roller Timing | High Volume Pump | Performance Lifters | FITS: Chevrolet Chevy SBC 350 5.7L V8

If the standard Thumpr isn't loud enough for you, it’s time to step up to the Competition Cams 12-601-4 Mutha Thumpr Camshaft. This is the camshaft for the guy who wants his Small Block Chevy (265-400ci) to sound like a dedicated drag car, period. While the original Thumpr is aggressive, the "Mutha" takes it to a whole new level of intimidation. Designed by the engineers at Competition Cams to deliver a barely-tamed, heavy-loping idle, this cam ensures that when you pull into a cruise-in or a gas station, you are the loudest, meanest-sounding vehicle on the lot. Let’s look at the numbers that create this monster. The 12-601-4 features a significantly increased duration profile of 235 intake and 249 exhaust @ .050, with a valve lift of .489”/.476”. By combining this long exhaust duration with the signature Competition Cams 107-degree Lobe Separation Angle (LSA), you get incredible exhaust scavenging and a power band that screams from 2,200 to 6,100+ RPM. This isn't a low-end towing cam; this is a mid-to-high RPM street/strip powerhouse designed to make massive horsepower in modified 350s and 383 Strokers. How does it feel? It feels raw and violent. The idle isn't just choppy; it shakes the whole car. It sends a clear message that you have serious horsepower under the hood. On the street, once you get past 2,500 RPM, the Mutha Thumpr pulls relentlessly hard all the way to the redline. Critical Tech Note: Because of the aggressive duration and higher RPM power band, this cam requires a higher stall torque converter (2,500+ RPM stall recommended) and rear-end gears (3.23 to 3.73+) to drive properly on the street. It is not for stock converters! Why choose the Mutha Thumpr? Because you want the ultimate combination of sound and fury. Competition Cams developed this grind specifically for hot rodders who want the audio profile of a high-compression pro-touring engine without the expense of solid rollers or high-maintenance race parts. You get the legendary durability of a Competition Cams hydraulic flat tappet with a sound profile that is absolutely unmatched in the industry. Don't just be heard—be felt. Install the Mutha Thumpr and dominate the street.

• IF YOU ARE NEEDING OVERSIZED PISTONS/RINGS/BEARINGS PLEASE SEND US A MESSAGE OVER AMAZON AFTER YOU MAKE THE ORDER TO LET US KNOW WHAT SIZE YOU NEED. WE WILL ALSO SEND YOU A MESSAGE REQUESTING YOUR SIZE. IF WE DONT HEAR FROM YOU IN 2 DAYS WE WILL SHIP THE STANDARD SIZE KIT. SIZES AVAILABLE: Pistons & Rings:STD, 020, 030, 040, 060 --- Rod/Main Bearings:STD, 010, 020, 030, 040
• The "Mutha" of All Idles (107 LSA): The ultra-tight 107-degree Lobe Separation Angle combined with increased overlap creates a severe, heavy-loping idle. Why Buy It: This is the "nasty" sound everyone chases. It sounds like a full-blown race car is sitting at the stoplight, offering maximum intimidation factor.
• 1) COMP CAM 12-601-4 MUTHA' THUMPR 235/249 HYDRAULIC FLAT CAMSHAFT - 2,200-6,100 RPM OPERATING RANGE. VALVE LIFT: 0.489"/0.476". 235/249 DURATION AT 0.050". 107 DEGREE LOBE SEPERATION. HIGH PERFORMANCE STREET/STRIP. ROUGH IDLE.
• 8) FLAT TOP PISTONS & PREMIUM RINGS: 10:1 Compression Pistons. 4 Valve Reliefs. 1.540" Compression Height.
• 1) SET OF MAIN BEARINGS, 1) SET OF ROD BEARINGS, 1) SET OF CAM BEARINGS
• 1) HIGH-VOLUME OIL PUMP - 5/8" inlet. High volume.
• 1) TRUE DOUBLE ROLELR TIMING SET - 3pc. set. True double roller. 3 keyway crank sprocket. 4 degree crank offset.
• 1) FULL GASKET SET - With 2pc Rear Main Seal
• 16) HIGH-PERFORMANCE HYDRAULIC LIFTERS & 1) SET OF FREEZE PLUGS
• High-RPM Street/Strip Power (235/249 Duration): With a duration of 235 Int / 249 Exh @ .050”, this cam moves the power band up to 2,200-6,100 RPM. Why Buy It: It is perfect for lighter muscle cars (Camaros, Novas, Corvettes) that are built to run hard on the highway or the drag strip, delivering explosive top-end horsepower.