Yah, because blown carb setups are common. Most people just slap on a P90 and go with EFI.
As for blow through with downdraft carbs, I think the primary problem with them, and why you don't see people doing it is the issue is clearance with the hood of the Z. There really isn't alot of space above the intakes, and a downdraft will take some of that up, and a bend for the actual intake will be even more.
If you want to do a draw through supertip, best of luck to you, but I need my Z to be drivable in below freezing weather as well, since it is my *only* car, and it gets cold here int he central valley of CA.