It'll be an increase but not as much as in a New Edge seeing as how you already have a 3.55. I say go for it though. Might as well build the rear while in there
I went from 3.31's to 4.10's a few weeks ago and on the way there at 70 the rpms were 1800 and on the way back after 4.10's at 70 I was at 2200 if that gives you much of an idea for an rpm difference. I'm pleased with them, but I haven't been to the track yet with them.
I went from 3.55's to 4.10's last month, I am happy with the performance improvement. I gained MPG around town and lost 2 MPG cruising at 70-75 MPH. I turn around 2500 RPM's at 75.
i have 4.10s and plan on going to 3.55s. but only because i have a different route in mind for my car starting this december
first gear is pretty useless. smokes em unless at the track. you dont just chirp second anymore either. you get a good 4-5 second squeel. but after my tune i just got smoke .hahah.
Super happy with the 4.10's in my car, although now that I've supercharged the car, the 4.10's are really only advantageous at the track with a proper drag radial. On the street, 1st gear is useless so I often start in 2nd. But, I still prefer the 4.10's over the lazy 3.31's I had originally. For an N/A car, 4.10's are perfect. For forced induction, 3.55's or 3.73's are ideal.