1950-1960 Big Twins

Size: 1/4 inside diameter x 1-3/8 inch length

This universal set of 8

• Direct Replacement: Replaces OEM #63798-99A and #63731-99

Intake and Exhaust Valve Spring Set for 1963 - 1972 Triumph 650 Motorcycles OEM #99-7037 70-4221 or 70-7400 Vendor_Lowbrow - BOM 1950-1960 Big TwinsAll KPMI valve springs are designed in house using sophisticated, proprietary design and simulation software programs. Their engineers, software, and 75 years of experience enable us to determine critical characteristics including stress, natural frequency, system harmonics, and fatigue life. Our spring manufacturing partners are U. S based companies that are ISO certified. The Super Clean Chrome Silicon valve spring wire we use is traceable back to