so i got my 4:10's put in a couple weeks ago and i love them. i also bought a diablochip from my friend and got it burned for the gears and to shift firmer. by the way i have an 02 auto GT. now that i put in the chip i can chirp 3rd gear on 275/40 street tires. that is soo cool to hear. my friends with 5 speeds can't even do it except a couple of them. as for gas mileage with 3:27s i got about 220 to a tank now i get like 205 to a tank. i went to the track the other day also and my previous time was a 14.5 @ 96 spinning and on my first run in humid weather launching off of idle on 20 psi in my nitto dr's i ran a 13.9 @ 98. just thought i would let yall know.