Are you ever going to boost it? Cause if so I wouldn't even go any higher then 4.10. I'd look at 3.90 or 3.73 in my opinion. 3.90 are PLENTY to get you off the line FAST. My first time ever at the track I launched from about 3k on my 315 555r drags and bogged and still hit a 2.006 60ft time which is pretty damn good for bogging and first time ever. Also do you research on them. I'd also like to point out that EXPECT gear whine that way if you don't have it then you'll be excited. I've had 2 different sets of gears and they both whine PERIOD. They are installed perfectly and still do it. Trust me, we've attempted to adjust it 3 times and it still does it and I got tired of buying oil. If your paying someone to do it make sure they know exactly what they are doing. I've heard a ton of horror stories with bad gear installs from shops that ruins the rear end due to bad bearing setups or reversed bearing caps.