So I finally finished making some significant changes to my truck's engine. I'll admit that I intended to pay someone to program my ECM for me and honestly, I'm still not loaded with confidence that I can do it myself. But before I get to any of that, I need to get my truck running correctly. Just wondering if I need to do a basic flash program to match what I've done before I can start data logging and fine tuning? Right now when I hit WOT from a stand still, it hesitates and backfires through the throttle body. Seem to run ok under moderate acceleration or if I stand on it at 25-30 mph. Here is a list of the changes I've made.
Vortec heads
Roller Cam (GM #14097395)
-Duration 196/206
-Lift .431/.451
-LSA 109
GMPP Intake (GM #12496821)
TBI "Ultimate Mods"
EP377 Fuel Pump (Currently set at 22psi)
Hypertech Power Bowl
Shorty Headers
Upsized Y-pipe (2" to 2-1/4')
Eliminated catalytic convertor
3" Catback
Eliminated EGR

I've double checked the timing and I have it set at factory spec 0 degrees. I've seen some people say this cam wants to be retarded 4 deg. but I'm hesitant to do this. I've also read that that the close LSA on this cam will not run on the factory TBI programming at all. I'd sure appreciate any input you guys might have.
Thanks, Joe