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Will 3.90's be too much?

This is a discussion on Will 3.90's be too much? within the Drivetrain forums, part of the LSx Technical Help Section category; I'm about to order some new gears for my rear end. My T/A is an M6 and I was thinking ...

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    Rice Hungry GottaHaveLS1's Avatar
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    Will 3.90's be too much?

    I'm about to order some new gears for my rear end. My T/A is an M6 and I was thinking of going 3.73 but I want to make sure it will be a noticeable difference. I know 3.90's will only hurt mpg a little bit, but will i definitely lose my bragging rights for reaching 160 mph? It's daily driven in the summer and i've never been to a track.

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    Veteran 0rion's Avatar
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    so are you wanting top speed performance or off the line performance? I'm not a fan of driving that fast on public roads not only because of traffic but because of the quality of the roads. I'd much rather have off the line perforamance for the street.

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    Make real real sure Johns00Z28's Avatar
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    Seems like most 6 speed guys go with 4:10's.
    Vote for Pedro.

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    M6 King Hot Black Trans-Am's Avatar
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    Go for the 4.10's. You'll just get to the 160 faster. It's the speed limiter that doesn't let you go past that and you should be able to do more if you removed it. If not do a power mod to get your top speed back.

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    Rice Hungry GottaHaveLS1's Avatar
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    I've never actually gone 160, only about 140 on the highway. But i want to know I can if I want. I think i'll probably go with 3.90's cuz its a DD in the summer and I need to get good mpg when I want to. I think I'd like more performance off the line cuz i usually dont go over 100 unless i'm on the highway. I think 4.10's will be too much for what I want.

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    2 SS's are better than 1 Jays00ss's Avatar
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    Had 3.90's in my 10 bolt and always wished I went with 4.10's. When I changed to my new 9" I went with 4.30's and absolutely love them 2150 rpm @ 75 mph in 6th with my new gears.
    2000 SS Camaro Heads, Large cam, Fast 90, 9"w/430's and locker, yada yada yada... you get the picture

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    go with the 4.10 for the m6 but if u plan on stuffing a larger tire under this thing u might want 2 think about a 4.30 ratio it will be less stress on transmission and also consider some axles and a carrier. go at least a 4.10 ratio u wont regret.

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    Rice Hungry GottaHaveLS1's Avatar
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    ehh, I don't think i'm gonna go that high. Right now my car sits at 2000 rpms when i'm doing 90 and that's awesome. What do you think my r's would sit at if I had 3.90's doing 90mph?

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    http://www.f-body.org/gears/ try this u will like it.

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    just rember ls1 like 2 rev

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    2 SS's are better than 1 Jays00ss's Avatar
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    Quote Originally Posted by GottaHaveLS1 View Post
    ehh, I don't think i'm gonna go that high. Right now my car sits at 2000 rpms when i'm doing 90 and that's awesome. What do you think my r's would sit at if I had 3.90's doing 90mph?
    First off why do you want to go that fast on a public street anyway? Your putting yourself and inocent others in danger. What exactly is your intentions? To me anything lower than 4.10's running primarily on the street is a waste of money. 3.90's are good for very high horsepower applications to stay out of 5th gear on the track (1/4 mile that is).

    Sounds like you want to play like we live near the autobaun so I don't know what to recomend since I drive at or near the speed limit on public roads most of the time.

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    Junior Member ChrisV 02 - Z28's Avatar
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    definately go with the 4.10 they are insane and I didnt suffer any noticable fuel mileage
    with 4.10's i have had mine to 155 (4 mile striaght flat shot with no interchanges and no traffic at the time) so your not gonna loose any top end, like said above you will get there quicker though.

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    Team Skeet Captain JHayesLS1's Avatar
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    I have 4.11's in mine. I love them. Would never go any smaller. I still get 220 miles to a full tank and I like accelerate.

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    Go with 410s. Who cares what RPM you are doing at 90mph if you are crusing at that speed you are just going to get tickets. I lost a whopping 1mpg going from 342s to 410s and I'm quite sure I could do 160 if I wanted. 390s will just have you wishing you went with 410s. Just be sure to get a good set of gears and break them in properly.

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    FAS02SS
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    3.90's

    Go w/4.10's. I've got an M6 and my gas mileage doesn't seem to have suffered and it really pulls now. I shift up into 6th more often than before but that is not really a problem. I had the guy do a tune when he installed my gears and the car felt way more powerful! I used Motive gears and they aren't too noisy.

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    Rice Hungry GottaHaveLS1's Avatar
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    Quote Originally Posted by Jays00ss View Post
    First off why do you want to go that fast on a public street anyway? Your putting yourself and inocent others in danger. What exactly is your intentions? To me anything lower than 4.10's running primarily on the street is a waste of money. 3.90's are good for very high horsepower applications to stay out of 5th gear on the track (1/4 mile that is).

    Sounds like you want to play like we live near the autobaun so I don't know what to recomend since I drive at or near the speed limit on public roads most of the time.
    Well it sounds like 4.10's is the way to go. Thats what my friend got for his 306 M5 Stang. I was saying that I go around 90 mph on the highway and occassionally around town. Do you really think i'm insane or something?? What did you buy an ls1 car for if you don't put the hammer down? I don't go to any kind of track, I just like to whip around some quiet roads in my town. No tickets in the T/A yet.... knock on wood.

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    Formulatastic yellowv's Avatar
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    Get the 4:10's. I had them in my black WS.6 and they made a world of difference. Gas mileage suffered very little and I turned maybe 200rpm higher at 80-90 on the highway. The only thing to be aware of is that they are quite a bit weaker than 3:42's (that is why I used new 3:42's when rebuilding my rear). If you run a sticky tire they will break pretty easily. I broke 3 sets of 4:10's with bolt ons on drag radials in a year. Also they tend to whine like a bitch. However they are fun as hell on the street from a roll. With just the gear swap I went from spinning into 2nd and chirping third to being able to spin all the way down the street when grabbing 4th.

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    Rice Hungry GottaHaveLS1's Avatar
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    Quote Originally Posted by yellowv View Post
    Get the 4:10's. I had them in my black WS.6 and they made a world of difference. Gas mileage suffered very little and I turned maybe 200rpm higher at 80-90 on the highway. The only thing to be aware of is that they are quite a bit weaker than 3:42's (that is why I used new 3:42's when rebuilding my rear). If you run a sticky tire they will break pretty easily. I broke 3 sets of 4:10's with bolt ons on drag radials in a year. Also they tend to whine like a bitch. However they are fun as hell on the street from a roll. With just the gear swap I went from spinning into 2nd and chirping third to being able to spin all the way down the street when grabbing 4th.
    4.10's in particular tend whine more than other gear ratios?
    I've got bolt on's and street tires and don't see the track either. We all know the 10 bolt is weak, but the gears should hold up pretty well right?
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    Member ApexVIII's Avatar
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    go 4.10's!
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    Formulatastic yellowv's Avatar
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    Quote Originally Posted by GottaHaveLS1 View Post
    4.10's in particular tend whine more than other gear ratios?
    I've got bolt on's and street tires and don't see the track either. We all know the 10 bolt is weak, but the gears should hold up pretty well right?
    Yes 4:10's do tend to be noisier. If you don't hook too hard they should hold up fine.

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