My opinion would be to treat the manifold like a max-5800-6000 rpm EFI build. The long runners are likely dosing their best around 5000-5500, so like Brent said, early intake lobe timing, and keep overlap in check, much like you would an EFI build, I bet it does OK.
I'd also go conservative on the header, even with a 482, you want everything dialed in to make a mid range monster
I do really like the idea of spacers if you have room. My hunch the bigger the better