I did a carb'd 302 w/ twin turbos in a mustang coupe a while back. If my memory serve's me correct, you'll need a boost referenced return style fuel pressure regulator, a EFI style fuel pump. Nitrile Solid floats, Enlarged Needled and seats (i think they were the largest you could get), Larger fuel jets (i just bought the entire fuel jet set that they had for a holly carb). mechanical secondaries, no choke, and no blow-out disc.

the turbo forums .com is the about the best place to go for carb'd turbo setups, they have a ton of good info on their.