At what point in my build up do I need to worry about maxing out my stock 99 injectors? After changing my intake manifold, I realized they are really easy to change, so now that I am not intimidated by them, will I see a change if I upgrade?

 

you need to change them when your duty cycle goes above 80%
-some people are fine cam only- some are fine after heads and cam

I was OK with 28# after cam only- I upgraded after 75 dry shot on top of cam only

 

99s have the crappy injectors cause they are smaller than the rest of the years(26.6 vs 28.8) I heard that the stock injectors are good enough for around 400 hp. if you are only boltons, no cam or nitrous, i doubt its worth upgrading. also, you will HAVE to get a tune after changin injector sizes, although not a full tune. otherwise u will run rich as hell

 

So I am good for now, I have only bolt-ons, no nitrous, no cam. I will change them when I do a cam swap since I will be getting a tune anyway. If I plan on going with a TR 224 114 cam, what size injectors should I run?

 

I'm not trying ot Hi-jack your thread, it looks like I'm in the same boat you'll be in soon.
I have a 99 Z28 Running a TR224 112 LSA cam, LTs, LS6 intake...full bolt-ons. It put down 381RWHP (460 at the flywheel). Are these 26.6 lb injectors holding us back? What are the 99' injectors good up to?

 

You'll be fine on the stockers up until heads & cam etc.

 

I'm running stock injectors with a TR224 cam. My duty cycle is 98%. A friend has an LS2 402 and is at 104% duty cycle. His car is also running pig rich right now. I have no issues either.

 

Not according to this
http://www.rceng.com/technical.htm
I put in these numbers top to bottom 460, 8, .50, .80, 58. It tells me I need 31 LB injectors. Am I using the wrong fuel PSI or BFSC?