how many lb's do the stock 99 5.3l fuel injectors flow? Could I swap out my injectors for some new injectors (need suggestions)? Also would that make some more power? just wondering because I have noticed a lot of guys with 99 year model trucks swapping out injectors for newer 5.3L injectors for some reason or another. Please enlighten me. Thanks

 

99=21.x pounds
00+=24.x pounds

Change the PCM to a 00 or newer year, then swap injectors and you'll easily feel the difference.

 

So if I was to change my PCM to a newer one and get retuned, would I feel any difference?