Beyea Custom Headers IDM-604-S1-B2 IMCA Dirt Modified Headers 604 Crate

The Beyea Custom Headers IDM-604-S1-B2 is a race-proven exhaust header system designed specifically for GM 604 crate engines in IMCA-UMP dirt modified racing applications. These professionally engineered headers deliver optimized exhaust flow to maximize power output from your 604 crate motor.

Key Features:

• Stepped primary tubes: 1-5/8" to 1-3/4" for enhanced exhaust scavenging
• 3" collector diameter with 4-into-1 design for maximum top-end power
• Heavy-duty steel construction with durable black paint finish
• Complete kit includes headers, gaskets, and hardware for easy installation
• Engineered for IMCA-UMP modified chassis applications
• Proven design used by top modified race teams and engine builders

Beyea Custom Headers has years of experience in race header fabrication, with each design thoroughly tested and refined for optimal performance. The IDM-604-S1-B2 features a stepped primary tube design that creates a broader power curve, helping your 604 crate engine produce consistent power throughout the RPM range. The 4-into-1 collector style consistently delivers strong top-end power for competitive modified racing. Sold as a pair.