Have a new 416ci LS3 engine going in with all new heads and a different cam.

Currently have stock LS2 injectors that the engine is tuned for with the previous setup. I believe I can find the values for the new 46lb FAST injectors that I have for the new setup.

Question...should I break in the motor with the LS2 injectors that I'm sure are correctly scaled or should I put in the 46lb inejectors and get them as close as possible before the tune?

 

use the 46's, or you will just have to tune again. you can use bigger ones all you want, just not to small of ones. Your duty cycle will just be lower...no biggie

 

I hope you have a wideband. If the tune is not close at WOT it can hurt ur motor fast. Good a/f ratio no prob.