Will these drop right in or will you have to change the tuning in the prom? I feel that my engine is running lean all across the board and possibly going "static" at full throttle. Engine dont pull during acceleration and just seems to fade off at full throttle. It ran better with the carb! This whole EFI swap is getting me down!!!

You will have to change the injector constants, or you can bump your fuel pressure on the 350 injectors and change the constants. How much horsepower do you think you are making on the 350. Read the stickys here and on fullsizechevy and it explains how to size injectors and make sure you get enough fuel. I have a set of 454 injectors I plan on getting rebuilt for my 355 build (still in the future as the 305 still pulls really strong), but even at stock pressures, the 454 injectors will not provide the fuel, so I will also have to bump my FP a little. I am thinking about bumping the pressure on my 305 injectors because I am running lean now.

yup i wouldnt put in 454 injectors. just raise the fuel pressure