You need to look at upgrading injectors at about the 690 rwhp mark. Some cars have gone a little further, some cars have needed them a little sooner, but 690 is a good ball park figure. I would recommend doing them with the blower swap anyways as you are going to want to make more power later down the road, might as well install them with the blower instead of having to take the blower off to install them however long down the road you wait. If you need a set of injectors, give us a call. We stock the 72's, 80's and the new 105's.