S/S Shaft Mount R/A System - SBM 1.5 Ratio

The S/S Shaft Mount R/A System - SBM 1.5 Ratio from PRW Industries is a precision serpentine belt and accessory drive system engineered for high-performance engine builds and street/strip applications. This shaft-mount configuration eliminates the factory belt routing limitations, giving builders complete freedom to optimize accessory placement for weight distribution, clearance, and component accessibility. Whether you're constructing a carbureted stroker, fuel-injected crate motor swap, or vintage restoration with modern internals, this system handles the critical task of driving alternator, power steering, and coolant circulation with reliability and clean aesthetics.

At its core, the 1.5 ratio design ensures proper rotational speeds across all driven accessories, preventing over-spin of the alternator or water pump while maintaining adequate output for electrical and cooling demands. The stainless steel construction resists corrosion and offers superior durability compared to cast iron alternatives, critical when the system sits exposed in modern engine bay layouts. The shaft-mount bracket design locks accessories in place with repeatable positioning and eliminates the alignment headaches common with traditional bolt-on brackets. PRW's engineering provides a compact footprint—weighing 14.3 lbs with overall dimensions of 9.1 x 2.2 x 20.6 inches—that integrates seamlessly into tight spaces without sacrificing rigidity or performance.

Mechanics and hot rodders favor this system for custom engine installations where factory serpentine kits won't accommodate non-standard block heights, accessory offsets, or aggressive stance modifications. Installation requires basic mechanical knowledge and standard hand tools; most setups are bolt-and-go once components are positioned. This solution works across small-block and big-block platforms with compatible pulley selections and delivers the professional-grade finish that separates a show-quality build from a backyard hack-job. Verify pulley fitment and drive belt length before ordering to ensure compatibility with your specific engine family and accessory combination.