3.90 or 4.10?
Thread Starter
Safety Car
Joined: Mar 2006
Posts: 4,448
Likes: 4
From: Sarasota Florida
St. Jude Donor '06
3.90 or 4.10?
I'm thinking of going to deep gears, 3.90 or 4.10. Aside from the obvious difference in ratio, and its attendant effects, is there any particular reason to favor one gearset over the other, like does one tend to be stronger/quieter/whatever?
Safety Car
Joined: Aug 2003
Posts: 4,988
Likes: 16
From: Hooterville, NJ
Strictly up to you, but unless you plan on tracking the car quite often the 3.90's will work just fine and give you similar ratio's to that of the the Z06 in first, second and third. In 4th gear you will have a 3.90 final drive where as the Z has 3.42. When I had the 4.10's in my car back when it was head and cam it felt very good under acceleration and the drivability was fine. At 70 mph it was turning around 1900 RPM in 6th. With 3.90's it will be less by about a 100 RPM or so. Gas mileage was not affected that much either.
Burning Brakes
Joined: Aug 2006
Posts: 789
Likes: 38
From: Shreveport LA
Depends on how much power you are going to want. I wish I would have went with the 3.73's now or even just stuck with the 3.42's. With over 480lb-ft of torque NA the 3.90's are a little much on the street and with plans for FI they will be ridiculous.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
7 Bolt-On Upgrades From Extreme Online Store to Level Up Your C6 Corvette
Pouria Savadkouei
Melting Slicks
Joined: Jul 2004
Posts: 2,826
Likes: 39
From: Central NJ
St. Jude Donor '05-'06-'08-'10
If you go with 4:10's and then add big power, you'll have traction issues. Actually you'll have the same issues with 3.90's, so I suggest you flip a coin. 
Team Owner
Joined: Jul 2004
Posts: 24,652
Likes: 298
From: NJ
St. Jude Donor '05-'08
having 342 then going to 410 and now having 373 all i can add is to think of your long term hp goals and to consider your driving style.
I went to 410 when I was into drag racing and my hp was below 400. even afte increasing hp the 410s were fine for quick street bursts and good on the track. to get full traction though i needed to run bfg drs.
this was all good until i tried road racing. once i did that i found the 410s were too much gear and that is when i dropped to 373s. 373s seem to be a good middle gear. i do wish they had a bit more pull in 6th gear at 60 mph but once you get to about 70 mph they are fine.
I went to 410 when I was into drag racing and my hp was below 400. even afte increasing hp the 410s were fine for quick street bursts and good on the track. to get full traction though i needed to run bfg drs.
this was all good until i tried road racing. once i did that i found the 410s were too much gear and that is when i dropped to 373s. 373s seem to be a good middle gear. i do wish they had a bit more pull in 6th gear at 60 mph but once you get to about 70 mph they are fine.
Night Owl for life
Joined: Nov 2003
Posts: 24,655
Likes: 4,502
From: Bugs Bunny should'a made a left turn here
seems kinda high RPM in 6th at that MPH...
also, when i get gears they will be 3.90 because, like others have said, i'd want to leave some room to add future power mods later.
Race Director
Joined: Mar 2000
Posts: 17,602
Likes: 20
From: Palm City Florida
Funny thing is when people say they are adding Twin Turbos, or S/C nobody ever mentions "Traction Issues"
Gears or Power Adders BOTH have the same effect on the tires...makes no difference how you do it..
Melting Slicks
Joined: Feb 2003
Posts: 2,966
Likes: 22
From: Frederick Maryland
St. Jude Donor '08-'09-'10-'11
If I had to do it over again, I would go with 3.90 or 3.73. I have 4.10 now with 443/397 at the wheels and even with 335 Pilot Sports it's hard to keep the car straight in first 3 gears. I'm currently thinking about swap to Z06 trans/3.42 set up.
Burning Brakes
Joined: Aug 2006
Posts: 789
Likes: 38
From: Shreveport LA
I will need et's on the back when I spray the 200 shot.
Thread Starter
Safety Car
Joined: Mar 2006
Posts: 4,448
Likes: 4
From: Sarasota Florida
St. Jude Donor '06
I note that no one has had anything bad to say about either 3.90s or 4.10s from a functional point of view, other than their opinions on the ratios themselves. I know that with some axles, going "up" a step in ratio can mean moving to a significantly weaker pinion (for example). That's really the kind of thing I was trying to get to here.
Team Owner
Joined: Apr 2001
Posts: 26,794
Likes: 613
From: Elmhurst, IL (West Suburb of Chicago) & Home of MEGA Horsepower
St. Jude Donor '06
4.10s all the way and don't look back ever. With a sticky tire like a drag radial you will be good to go and the 4.10s will give you a slight edge over the 3.90s in pure acceleration and make 6th gear even more useable. Don't forget, the fastest 10 second stock cubed heads and cam documented C5 1/4 mile times on a M6 tranny (on the vette forum) have all been done with 4.10 gears!! 
Let's face it the difference is going to be marginal between the two gears and go with the 4.10s and don't look back!!
I had 4.10s in a Z06 and LOVE IT and hooked well on the street with BFG drag radials!
Let's face it the difference is going to be marginal between the two gears and go with the 4.10s and don't look back!!
I had 4.10s in a Z06 and LOVE IT and hooked well on the street with BFG drag radials!
Last edited by Mopar Jimmy; Jan 4, 2007 at 03:02 PM.
