I was wondering if I upgraded my injectors, would it be alright to get like 42# injectors for my application even thought I don't need them right away? I am not sure what I am going to do in the future and the bigger injectors don't cost that much more. I am able to program the computer for the as well.

 

IMHO there is no need to go with that big of an injector unless you plan on building your motor and running a supercharger.

 

I just want lots of headroom incase I add nitrous or something. They arent much more and I never really want to switch injectors after I buy some.

 

Large injectors will give you a poor idle quality, unless you are running extremely high fuel pressure, which causes its own problems. The problem is that large injectors don't atomize fuel well untill they are "pushed" to perform in their upper 65% range. The problem is that the nozzle/pintle area is MUCH larger than stock so at low pressure (idle) they're squirting in droplets of fuel instead of a fine spray. Also, the pintle/needle has a much higher mass, so even if you shorten up the injector pulse-width significantly, it will still be sluggish compared to stock in opening and closing. I believe that a 32-36 pound injector would be more than what you need to meet your goals. Keep in mind that the factory 24lbs is adequate up to over 450+hp. I'm personally running the factory 24s w/ the setup listed in my sig. According to the sniffer, even @ WOT and 6400rpms, I'm still getting enough fuel.

 

Not a lot of downside, and in very high HP applications, there can be a performance advantage in getting the duty cycle down below the "normal" design point of 80%. Where you run into problems is "turning down" the large injectors to provide sub 1-millisecond pulse widths at idle, and low loads. The stock PCM has limits. Most high impedance injectors have limits in the minimum time required to open and close them (offsets). Generally larger injectors are low impedance and open/close faster. There is a "black box" add on to allow the stock PCM to drive low impedance injectors, but that is an unneccesary complication at this point in your buildup. A good set of injectors won't cost that much, and you can always recover part of the cost when you need to upgrade.

 

As for being concerned about adding nitrous, I recommend "wet-kits" to anyone without significant nitrous knowledge and the funds to do dyno-tuning as well as install several safety measures to protect their motor.
IN case you don't know, a wet-kit nitrous system adds fuel w/ an included nossle, thus the injectors are not a concern. Systems like N.O.S.'s dry system have their advantages but are more risky. They either 1)increase the line pressure in your fuel rail to force for fuel per injector pulse out OR 2) require reprogramming of your injector pulse-widths to a very exacting degree to insure that you have the proper mixture.
Go wet.