Every car is different. Well, an LS1, a 3V, a 4V, and a 2V are all going to be different is what I mean. As long as you got the tire to back it and are on top of your shifts, I think you'll drop a good bit of ET. Your car is going to rev way quicker with the gear and less rotating mass, so even if you don't have the tires to hold it the car is still going to bring the RPM up a hell of a lot quicker than it does with 3.73s and the steel DS.
I've done 4.10s and an aluminum DS on other cars. It makes a difference for sure.
2015 Focus ST, Livernois Tuned.
O/R Downpipe, Steeda mounts.