It's been years since I've posted here, but for the sake of someone else looking for a DIY project for a cheap V8 ITB set-up, check out the LS1 Tech page in which I fabricated a set-up using a highly modified aftermarket intake, some Chrysler LHS throttle bodies (Holley 48MM), and some home fabrication and welding. Using the Holly HP EFI system, the total cost of getting it up and running (mechanical and electronic) was about $2400 for everything. Again, a lot of home-made stuff, but nothing that a drill press, and common sense couldn't handle. The photos are a bit dated, but nothing has changed other than the system runs very well (took awhile for this old-school carb man to tune with a computer).
http://ls1tech.com/forums/fueling-injection/1269857-poor-mans-ls1-itb-fab-up.html
Also, my signature still works, so anybody interested in viewing the ITB set-up for a DIY'er, you can view the documentation photos (lower link), but look under the album called Manta ITBs instead of the Z-car albums
Terry