My doomed 408 build

There’s absolutely nothing wrong with the springs supplied with the RPM heads........ when used with a cam they are suitable for.
Using the .575 max lift recommendation from Edelbrock can definitely get you into trouble.
Imo, the best use for those is an under .525 lift hyd cam that doesn’t have real fast ramps, used in a motor that won’t be required to turn a lot of rpm.