The Manley Street Master series delivers upgraded valve springs and components designed specifically for street-driven performance builds. Made from high-tensile chrome silicon steel with precision shot-peening and heat treatment for long life, Street Master parts offer improved valve control, reduced stress, and dependable performance over factory components. Ideal for naturally aspirated and mildly modified engines, these components give you stronger valve-train stability and smoother operation for spirited street driving without race-only complexity.