318 Engine Build help

I'll look at getting better springs. I know the magnum springs are a different size (odd size). I've searched, but can't find what size (I've found it somewhere before, but can't seem to find it now). Anyone have a part number for them, or can lead me in the right direction?
As for the crosswinds intake, what kind of issues are there with it? Bad casting? Runners?
I think it already has a 650 on it (still haven't seen the car in person yet), so if that's enough, that'll save me enough to use on other things.
I picked up some Magnum valvecovers for a steal (shipping was more than they cost). Thanks for the help. I'm sure I'll have more questions, especially when I physically start the build.
Oh, any idea of what the machining will cost me?