[Heavymetl]

The TB in your pic is a 3 bolt, so it'll bolt right up to the LS6 intake. No problems there.

Your accessory drive will determine which balancer and water pump you will need. The spacing is different between the truck, f-body, and Vette systems. As you can see in your pic, the truck balancer/pulley is furthest from the block of the different stock setups.

The injectors are also a piece of cake. They'll use the EV1 style injector and be sure to have your tuner update the injector data accordingly. If I were you I'd just buy the ev1 pigtails and cut/re-wire the harness.

The steam lines will need tweaked, but I'm honestly not sure as I've never personally swapped on a car intake and kept the truck steam lines. Either make your own or source LS1/LS6 parts.