Best Intake for a 408

Demonx2 said

In my specific case, any work done to open up the manifold intake ports would have caused an overlap condition (step) entering the head port. They aligned line-to-line almost like it was one long seamless runner. On each port no less! Yes, I was surprised but it was what it was so I didn't touch it. Like I said before, if this car wasn't so much fun in its current configuration, maybe I'd try the Air-Gap I have for it. Maybe one day I will and if I do, I'd of course post up the results in my thread I have for the car.

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I saw that in your detailed post. Got to love it when things line up the way they should.

My curiosity is mostly aimed at the plenum size and shape, and the runner size and length. An Air-Gap would be in a league of it's own.

As a side note, I just got my 5.9 Magnum running in October 2021. It was a used engine with issues that I went through and fixed up. I originally installed the Chinese copy Air-Gap that came with it. Before driving the car at all, I switched to an M1 single plane while fixing an oil leak. There was an immediate difference in throttle response where the dual plane Air-Gap style seemed snappier, but the single plane is still working nicely on the street. No track times to report on this one.