Gears and Dyno

Hi everyone i have a 89 mustang with a few bolt ons. The problem im having is i have leaking fuel injectors near the hats so ive tried replacing the o rings and they still leak and inspected the fuel rails and they appear to look fine. So i have a set of 24lb injectors and everything else i need to go with it. I wanna go aheahd and do the swap but should i have My gears installed when I dyno or does it make a difference?