[jonnyk]

I would be looking at a more serious cam than an E303. Those are huge heads and you should look to extract some of their potential. I would be looking into the Comp Cams XE series, something like the 270HR. It is a specific blower cam and offers way more valve lift than the E303 to help extract the flow potential of those heads, and also a wider lobe separation for better use with boost. It's specs are 114° LSA, 215/224 duration @ 0.050", and .533"/.533" max lift. Make sure those AFR valve springs are up to the task.
I think the GT40 is extra money for nothing...the Cobra intake is a great performer, but the problem is that the 70mm throttle body you have is too big for it, it only accepts up to something like a 67mm throttle body without modification. You could use a die grinder and open up the inlet a bit I would imagine.
I personally recommend Edelbrock intakes for street cars and run one myself (the Professional Products knockoff version). They offer better distribution to the runners and more flow than an out of the box Cobra, plus they're much easier to have the upper ported.