@skep419 the valve springs in the stock magnums are junk and barely adequate for the stock roller cam. With a factory intake you’re all done at about 5200. No reason to spin it more than that. If you’re going to keep the stock cam, throw a set of springs on it and you’ll get a few hundred more rpm out of it. It won’t make more power but you can shift a little higher. As they are stock, they’re all done making power way before the safe rpm limit. There are a few shelf comp roller cams that are a really nice upgrade and Holdener has some you tube videos on em.
