Description
Transform the performance and sound of your classic Buick with the COMP Cams Mutha' Thumpr™ 227/241 Hydraulic Flat Tappet Camshaft for Buick 350 (Part # 92-601-5). Engineered specifically to maximize exhaust overlap, this camshaft delivers an unmistakably hard-hitting, rough muscle car idle cadence without sacrificing responsive street power or low-speed drivability.
Designed with an early exhaust valve opening, extended exhaust duration, and a tight 107° lobe separation angle (LSA), the Mutha' Thumpr profile optimizes cylinder scavenging across the 2,200 to 5,800 RPM operating range. It is the premier choice for enthusiasts seeking a heart-thumping, race-inspired exhaust note and strong mid-range pull in Buick GS models, Skylarks, and classic hot rods.
Camshaft Profile Specifications
| Specification | Intake | Exhaust |
|---|---|---|
| Duration @ .050" | 227° | 241° |
| Advertised Duration | 287° | 305° |
| Valve Lift (1.55:1 Rocker) | 0.469 in. | 0.457 in. |
| Lobe Lift | 0.303 in. | 0.295 in. |
| Lobe Separation Angle (LSA) | 107° | |
| Intake Centerline (ICL) | 102° (+5° Advance Built-In) | |
| Operating RPM Range | 2,200 – 5,800 RPM | |
| Valvetrain / Core Style | Hydraulic Flat Tappet (Cast Core) | |
| Grind Number | B350 287TH-107 | |
Engine Compatibility & Drivetrain Requirements
- Engine Application: 1968–1980 Buick 350 CID (5.7L) Small Block V8
- Torque Converter Requirement: Requires an aftermarket 2,200–2,500+ RPM stall torque converter on automatic transmission applications to maintain proper idle quality and acceleration.
- Gear Ratio Recommendation: Best suited for performance rear axle gear ratios of 3.42:1 to 3.73:1 or numerically higher.
- Compression Ratio: Optimized for 9.0:1 or higher static compression ratios.
Crucial Installation & Valvetrain Notes
- Spring Upgrade Required: Must be paired with matching performance valve springs (such as COMP Cams 968-16) to ensure proper seat and open pressures, maintain valvetrain stability, and prevent high-RPM valve float.
- Flat Tappet Break-In Protocol: Mandatory engine break-in procedures must be followed. Use high-zinc (ZDDP) break-in oil and break-in paste on all lobes and lifter faces during assembly. Run the engine between 2,000–2,500 RPM for 20–30 minutes immediately upon initial start-up.
- Lifter Replacement: Never reuse worn flat tappet lifters with a new flat tappet camshaft. Always install a fresh set of matched hydraulic flat tappet lifters (COMP Cams 805-16).
Details
Shipping Information
- H2.75"
