Have a 99 Silverado 2wd 5.3l
At wot it runs highs 9s low 10s on afr gauge with or without the nitrous.
Also sometimes hard start in the cold.
Mods.
Stock 5.3l with headers no cats e fans
Trans corvette servos
Rear end 4.10s posi

I'm at a stop still ,any help would be appreciated
I bout the truck with mods already done.

Don't know to much about injectors in the truck if factory or not.