The Ford Racing PAC 1219X valve spring is a single replacement spring specified for use with M-6049-Z304DA. Detailed spring data lists a 1.207 in outer diameter, small-end ID .650 in, installed seat load of 145 lbs at 1.8 in, open-valve load of 358 lbs at 1.175 in, a spring rate of 340 and a maximum coil bind of 1.100 in. It’s offered as a high-quality replacement component for compatible valvetrain assemblies.
Ford Racing PAC 1219X Valve Spring - Single (for M-6049-Z304DA)