1968 383 stock cam specs
Darren,
Valve Springs
Compu-Cams.....#911-16...........{#122 lbs. Valve-Closed ~ #309 lbs. Valve-Open}
or
Mopar Performance...#P3690933
Are nearly identical in Load-Rate Spring Pressure.
Both are designed for Hydraulic Camshafts with Lifts between .450" and .500"