alright here is the problem maybe i missed what going on with your build in another post but i can start of telling you this.
The injectors in your truck are not maxed out as they sit, I personaly ran 4lbs of boost on a stock tune with stock injectors and upped my hp from 126RWHP to 172RWHP without even tuning it what so even.
If you were to get the bigger injectors from a 350 or 454 on a stock tune you will run rich all the time and will probably end up washing the pistons. I ran my truck with a stock chip and 350 injectors once after building my motor to see if it was close enough to drive it home,... and it was crazy rich to the point we shut it off instantly. You would have to get a custom chip for your truck to run right with the bigger injectors.
www.tbichips.com could take care of it....
That was on my truck with a edelbrock 2114 intake with holley tbi conversion plate, 2000 vortec heads worked over with oversized undercut manley stainless valves, edelbrock tubular headers, and a .500 lift cam with 260 ad duration on full roller rockers...
Now if your looking for a better running truck all around without doing alot of work, call brian at TBI chips he is working on my tune with my truck right now. just goto
www.tbichips.com and tell him brock sent you lol thats the easist fastest upgrade to your truck to get another 10-15hp maybe out of your tune.
now other low buck for the bang items on a tbi motor
coil factory one is horrible get a msd drop in gm one or go big and wire it
air intake, get a open element filter to replace all that steel and routing crap.
exhaust, free flowing cat and muffler
Good NGK plugs and some Accel or msd wires
next level
y pipe its horrible..
better valve springs, so you can wind it out past the 4400 rpm area its at now
cam, .. comp and crane have some nice ones - timing chain to support the extra valve spring force and rpms
Headers
adj Fuel pressure regulator
350 injectors
Next level yet, (where you would start to need 350 injectors)
Vortec heads from a 96+ with or without some work on them (requires alot of work to make this conversion. though)
2114 edelbrock intake and holley conversion plat for tbi
Full roller rockers
MSD 6a or 6al or crane box
Then... where the bottom drops out..
Supercharging bolt on kits from
www.wynjammer.com
Fuel pump
More tunning from TBI chips
depending on miles on the motor a rebuild with forged internals...
Meth injection
etc etc
So depending on what your goals are you will be 100% better off just putting the money into upgading what you have. I am running TBI and plan on running it until i have some kinda big problems or see major gains going to somthing else.
The biggest gains in fuel injection to be had past tbi is just getting a 2114 intake with 6 real injectors controlled by a 96+ ecm and harness so it will have the ability to run a 2 bar map for running boost later on.
Should give you some ideas!