Safe RPM for a 408" Magnum?

Yup, further testing revealed that the issue has been resolved. It power shifts hard with no sign of hitting the rev-limiter. Even with a smallish cam, this thing gets up and frick'n goes.

I love the Hooker Aero Chambers. They are nice and quiet when you are cruising, but really let the thing breath when it's wide open. The sound of a 408" Magnum V8 at 6k+ is an awesome thing! I'm sure it could be heard for miles and caused a few smiles.

Now, I'm really looking forward to installing a more appropriate cam for my intended use. Thanks again each and every one of you for your insight and time.