Valve Spring Requirements?

[talos]

I currently am running Edelbrock Performer Heads on my 427 side oiler, medium riser dual quads. I am switching back to Webers. The heads spring pressue is Seat/150, Open/355. They only have been ran for 4 Hrs. Can I install a new mechanical flat tappet cam without changing the springs?

[blykins]

Originally Posted by talos

I currently am running Edelbrock Performer Heads on my 427 side oiler, medium riser dual quads. I am switching back to Webers. The heads spring pressue is Seat/150, Open/355. They only have been ran for 4 Hrs. Can I install a new mechanical flat tappet cam without changing the springs?

A lot of spring load without a nitrided cam and EDM lifters.

Even if you got the cam and lifters like that, you'd need to be well below those loads for break-in.