COMP Cams Camshaft C409 47S283THR8

This COMP Cams Thumpr 4/7 Swap camshaft is designed for Chevrolet 348 and 409 big-block engines. It's a hydraulic roller camshaft, meaning it uses roller lifters to reduce friction and wear compared to flat tappet designs. The '4/7 Swap' designation refers to a specific firing order modification that can help improve exhaust scavenging and overall engine breathing, especially at higher RPMs. This camshaft is intended for high-performance street applications and is known for producing a distinct, choppy idle sound that many enthusiasts appreciate.

When installing this camshaft, COMP Cams suggests it's suitable for use with a stock torque converter, but you'll see the best results with a higher stall converter, ideally 2000 RPM or more, along with appropriate rear-end gearing. This setup will help keep the engine in its power band more effectively, especially off the line and during acceleration. The camshaft features a 227-degree intake duration and a 241-degree exhaust duration at .050 inch lift, with .477 inches of intake lift and .480 inches of exhaust lift. These specifications indicate a camshaft that offers a significant performance upgrade over stock, providing improved power and torque across the RPM range while still maintaining reasonable street manners, albeit with that characteristic thumping idle.

It's important to note that this camshaft is not CARB approved and cannot be shipped to California due to emissions regulations. For optimal performance and longevity, ensure you follow the manufacturer's recommended installation procedures, including proper break-in for hydraulic roller camshafts. This camshaft is a solid choice for builders looking to add a noticeable performance edge and a classic aggressive idle to their Chevrolet 348 or 409 engine.