Upgrade your Dodge Cummins engine with the high-performance Comp Cams 973-1 spring. This steel spring is designed to handle up to 550 horsepower, making it perfect for those looking to boost their engine's power and performance. Made by trusted manufacturer COMP Cams, this spring is a must-have for serious enthusiasts looking to get the most out of their engine. If you have 3000-4000rpm governor springs on your p-pump you need one of these. At higher RPM the stock spring cannot spring back and supply enough fuel.