Update: Here are the engine specs:
GMPP vortec to tbi intake
comp cam 12-388-4
hypereutectic piston 18cc dish
4340 steel 5.7" I beam rods
3.750 Stroke Crankshaft 9000 series
decked and balanced internally and externally
So it looks like the engine is going to be more around 370hp, so I was wondering if maybe just using the 454 TB with the 350 injectors and upping the fuel pressure would be able to support this motor. Any help is greatly appreciated!!