I would go in tank too, from a reliability stand point, and the fact that your tank isn't baffeled at all. When the tank gets low, that electric fuel pump pushing the fuel to the engine at 58 psi, is going to starve for fuel during acceleration and cornering. On a carb'd engine you don't notice it because the fuel bowls hold enough fuel for the pump to catch up, but on an EFI engine, the stumble will be instantaneous. With a tank like you have, I would use a factory sender/fuel bucket type pump, that way you always have fuel at the pump. You can either buy something like a Vettworks adapter or make one since they're not very complex, then get a pump from a truck that matches the depth of your tank, Tahoe's are shorter than Silverados.
http://www.vetteworksonline.net/cata...qln9hmmunf50v5