i didn't really have to post this question here i guess, although an MS is going to be used, but anyway:

my stock NA injectors seem to be working ok, although they are obviously old now. i'm building the MS right now, so that's going in and i won't HAVE to use the stock injectors.
now, although i am not close to maxing out the stock NA injectors (i'm actually running leaner than stock right now), i have a pair of T2 550cc injectors that have been cleaned and i want to use for that reason alone.
now, are there any disadvantages to using those bigger injectors? i won't put them in if they are going to use more fuel or hard to tune with MS, etc...

 

if you use them as secondaries they'll cause no problems... you'll just have to change the scaling factor for staging.

 

yeah, i should have mentioned they would be secondaries