Foreign valve springs in a Magnum

Fishy is right on the money. If you are running stock magnum rockers then they are not adjustable and you just torque the rocker bolts to pre load the lifters and call it good.

I am running Chevy springs on my magnums, but I have adjustable 1.6 rockers, comp cams guide plates and push rods. Here is my set up that is adjustable.