Can I run B series Pro stage 1 camshafts with my OEM factory valve springs and retainers?

No. The lift these camshafts generate would cause factory valve springs to coil bind and break. In order to safely run Pro Stage 1 camshafts, you must upgrade your valve springs and retainers. Skunk2 Pro-Series retainers have been carefully designed to provide clearance between the rocker pad as well as the valve guide when used with aggressive Pro Series Camshafts.