You could put a holley steath ram intake on it, you'll have to drill it out to get it to bolt to the vortec heads. Then you can run conventional injectors. You'll have to splice the injectors in to the harness, and lengthen the wires for everything else(TPS,IAC,MAP,) and ditch the EGR. You could put an inline pump in. or run a walboro intank. But this kinda setup isn't cheap.
They don't make bigger stock type injectors. I suppose you could run a stand alove injector driver, and mount a couple injectors in the intake but it would be difficult to tune to say the least.
01 ecsb 5.3 4x4 z71
Avalanche 17s and a pant load of miles
61 Corvette
350, 4 speed, 4.56's
32 Ford 4 door sedan
keeping it "stockish"