What is a good combo for turning high rpm?

Just thinking out loud here....... You want reliable, RPM, and 450HP??

I would de-stroke the 318, I wonder if there is any of those 3" SB cranks laying around anymore.

What was the REAL trans am motor? Wasn't it a 297 cu in 4.04 bore engine? Since you have an already proven 318 block, I would keep it,m and mimic the de-stroke 340.

I would....

Run a quality (but light) set of rods, your choice.
Run a light (think Ross) piston, made for your stroke.
Guitar jones oiling mods and the like, get on moparchat and read Sanborns too.
Get real serious on the heads, like the W2? maybe Aluminum? That RPM will take cam, and that cam will take compression.........
Solid roller valvetrain. I built a 318 that ran happy to 7500 with a roller Mopar circle track cam, I think the duration was 290/290, with .590 lift. I had Harland sharp rollers on it too.. It wasn't HELD at 7500 though..... Oiling system mods, (very extrensive) and clearancing is a must. most think because they have hit 8K before, that what they have will last at 8K. MOST street/strip engines wouldn't run a couple minutes at 6K, let alone 8K.

I would find a guru, thats not on the net, to walk you through the extensive steps to building a long living high RPM motor. Where abouts do you live?