Help with my first engine build (5.9 Magnum)

ValleyRat said

That's great information. I 've been told that the stock Magnum cams are very whimpy, but wasn't sure when I would have to start worrying about upgrading keepers and retainers with my choice of new cam. Its nice to know that I'll be able to use stock components (aside from valve springs).

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The OE roller cam will fall on its face right about 4500. Mine does at least. Great power until then. Don’t go crazy on the lift as the head flows only so good so far. Max lift area for the stock head should not really exceed .500. There really is no point. Just increase the cams duration to for your axle ratio and plan.