another 10 bolt ready to die. you see my title sponsors. i want a new one and i need some guidance gear ratio etc. ls6/ viperized,shot peened,cryoed, t56 and existing 3:23 i'm pulling around 1800 rpm i don't think this good for the motor to be going that slow of rpm in 6th i don't think i'm in my power band for engine and fuel efficency. the only thing i can relate to is harleys and keeping them at 2500 to 3500 in every gear proved optimum efficency is this the same on ls motors. what gear ratio ? i know stock 6spd is 3:42 what about 3:50 ? alot of money going out i want to make the right informed decision on the whole package . i would be mainly driving on street,couple of 1/4 miles a year or so and dodging the orange cones. i don't want to make my gas milage suffer to much but i think it's not burning fuel very well on the oposite end of the spectrum. i'll check back with you guys tomorrow and see who can deal me good or should i go to strange directly? thanks.. the oldman..........

 

It would be a pleasure to help You with Your rearend purchase. My parts line is listed below or message if You prefer.

Thank You,
Carl Loder

 

+1 for Carl, he will set you up

 

This may help you out:

https://ls1tech.com/forums/gears-axl...t-install.html

 

o1ssredda4, i see from the amount of posts and your 12 bolt write up that you could give me some input on the 12bolt does it whine after track time? deflection of axle tubes? the zerk fittings at the end of the axles is that because of "c" clip eliminaters? i think i'd like to keep the 'c' clips so the fluid runs to the axle bearings. do you forsee that to be a problem? i don't think i need to worry about an axle walking out on an occasional auto cross? i mean really how often do you see a'c' clip fail? i'm new at this i might aproach 500hp at most in the future. i had a 12 bolt built for a 67 camaro that i sold before it ran and it was put together with 'c' clips and the whine tell me more please thanks for your patience... the oldman......

 

By the design of the ends/seals it doesn't appear that the gear oil lubes the wheel bearings. I asked Strange how often I should lube the wheel bearings and the tech said "I dunno, maybe every 10k miles"......I know we all know that the Mosers seem to be quiet and then after a few hard launches they start whining. You don't really hear about the Strange units doing this so I'm not too worried. I think with Strange the whine will be from the gearset depending on who sets it up, and you'll either have it or you won't.

 

i understand . i've talked to the local mech. and he said with my 6spd 3:55 would work good . he has a yenko nova 4spd with 3:55 and says it does pretty good his brother told me to go with 3:73 but i want some gas mileage also thanks, the oldman.....

 

With the double overdrive in the T56 gas mileage will always be good. It allows you some freedom in rear gear selection. I personally like the 4.10s behind the 6 speed cars.

 

A couple things I would consider here...

1) With a 6spd, the whining you will get after a few hard launches on a 12 bolt will likely not be determined by the manufacturer of your 12 bolt. It doesn't seem to matter whose 12 bolt it is. The shock on the drivetrain from a 6spd doesn't mix with the 12 bolt well on a torque arm setup. Almost everyone complains of whining after a few trips to the strip. Some have theorized the location of the torque arm mount on the 12 bolts causes the torque arm to distort the housing after repeated high rpm launches. Most 6spd guys shy away from the 12 bolt for this reason. Autos run them and don't seem to have any problem, but the transfer of energy launching the car is different with an auto. It's not as severe.

2) You can't compare a 4spd nova with 14 inch wheels to a 6spd camaro with 16 or 17 inch wheels and look at the same rear end ratios. I believe the Muncie's first gear is similar to the T56's (2.66), but the tire size is different between your two cars. You will need a deeper set of gears to get the same final drive ratio with your car that your friend has. Best thing you could do here is measure his tire size and yours, find a final drive calculator online and punch the information in (tire size, first gear ratios, and rear axle ratios) for each car to compare what the final drive would be. Most guys seem to like 4.10s with a 6spd. You shouldn't lose too much MPG because you still have the double overdrive.

Regarding your choice of axle (12 bolt), here's some good info from one of our sponsors: http://shop.brutespeed.com/Brute-Spe...nformation.htm

 

Whether or not a 12 bolt will work well behind an M6 is relative to the whole combo. Vehicle weight, overall HP/Torque numbers, clutch selection, driving style, and intended use all play huge factors. I can say this, Strange cases are molded differently then Mosers, which is one of the reasons I took pictures of mine for anyone that was curious. I find far less complaints with Strange's stuff then Moser's....is this a product of sheer production volume? Perhaps, but I chose Strange for my own personal car because I didn't want to risk it.

 

I personally wouldn't run any 12 bolt with a 6 speed just because of what I've read over and over about them whining from repeated hard launches. If your mainly doin road cross, then I'd say a 12 bolt would be fine.

As far as gears go, If you seriously wanna use every bit of power you have, I'd go with no less than a 3.73 in a 6 speed. With 4.11's my car is running 2080rpms at 79mph and has plenty of pull from thst speed in 6th and still gets 27mpg's avg on interstate. Mixed driving (city/hwy) is about 19mpg's. It pulls good everywhere and also allows me to shift less around town without having to rev high to skip gears. Start in 1st or 2nd then shift to 4th at about 20mph and that gear will pretty much run any in town speed limit with ease. Seat of the pants power is deceiving, but not entirely. What I mean is it will feel like its a full second faster when in all actuality its maybe .3 tenths faster in the 1/4. Definitely one of my favorite mods on my car.

 

That just proves the point for gearing with 2 ODs available vs. 1 in an auto. An auto would turn 3k in the lower 70 mph range (with a stock tire) while the M6 shows no less then a thousand rpms lower at the same speed. Much more versatile. Perhaps that is one of the reasons the new autos have 6 gears.....

 

The new autos are nice. My tahoe has a 3.08 final gear and sits at about 1900ish at 80mph. The tire is a 265/60/17. Guessing it's around 28" tall

 

I'd be interested to see if Strange's case molding makes any difference with an M6 and whining. I did some searching around and it looks like the results are still gear whine if you take it to the track and launch on sticky tires with a M6, even with a Strange. Strange's case and torque mount setup is superior to Moser's though, when it comes to 12 bolts. I also agree that intended use will play a factor.

OP, if you don't want to take it to the track, then a 12 bolt will probably be fine. If you are like me, however, to pay 2K+ for a rear and get gear whine after a couple trips to the track would make me mad. I would love to put a GM based rear in my car, but the possibility of shelling out the money then picking up a lot of annoying gear whine keeps me from doing it.

 

Good post, I have to agree. When I first got my Strange 12-bolt I hammered on it quite a bit on the street and the rear did become noisier. The past year I've been driving my car pretty much like a normal car, instead of a drag racer, and the rear has quieted down to the point that it's no noisier than my 10-bolt used to be. I love my 12-bolt, but the prevailing wisdom seems to be spot on: if you're gonna race your car with an M6 get a 9" or something else comparably strong.

 

My strange 12 bolt is more annoying than a politician - changed ring and pinion, quieted down a lil then, but now its louder than ever. I would never recommend buying this unit for someone who drives their car daily. If I knew then what I know now- I would have gotten a 9" from midwest and called it a day.

 

I think the experience you have with the Strange 12-bolt is tied-in pretty closely with how you drive your car. For me it was the right choice, but I can see that for you it wasn't. My main reason for getting the 12-bolt was that I wanted 4.10/ 4.11 gears but I didn't want those gears in a 10-bolt. There was nothing wrong with my 10-bolt when I swapped it out.

I would have went with a 9" but at that time there were various install issues and modifications that I didn't want to deal with. It seems that nowadays they've become much more user friendly to install. So I'm pretty sure that if I was buying a new rear today it would be a 9", but that's not saying that I'm unhappy at all with my 12-bolt. FWIW.

 

thanks folks for all your help, i tried to look at the sticky at top of page but like i said before this computer stuff is new to me it would not let me in. question the weights of 9inch, s60,and 12bolt. i'm right at 400hp and 390 torque and want to keep it that way . my friend has me keeping my stock ls6 cam because of the rpm range i want my power in. that s60 is looking better and better. i just dont know. i don't want to get the back of the car done and then jump back to the front. i have a spohn torque arm, panhard bar,and lca's thoughts on whine. one persons whine is different than anothers. guess i need to bite the bullet and live with it . i have another friend that is buying the ole' ladies durango in a month so i have time for more researce. i want to get this done before holley ls fest cause i live in missouri and want to drive to it and play,then drive home with no issues. thanks again.. the oldman.........

 

If you do decide to go with the s60 +1 for Carl at CRP. I can't reccomend his customer service highly enough. The man must have his phone attached permenantly to his body. Always answers and sounds happy to hear from his customers. As far as installation, i put mine in with a cast on my left leg so they definitely bolt right in.

 

talked to carl today, the rumors are true. great ,knowledgable,smart and one heck of a good guy from what i have gathered from our conversation he's got me going S60 oh yeah!! and all the help comments and pictures from fellow LS nation folks has really helped me make an informed decision i thank you all, now i gotta decide on the gear ratio. does anyone know if the f-body. org gear ratio calculator is still active?? i tried it a couple of months ago and didn't go thru. course i'm a tech dummy anyway. nutshell: rpm in 6th@80mph with 3:73 and with3:54?? anyone? oh carl the ol'lady gave me the green light for the S60 so i'll go to the country and look at those backing plates on that v6 car we were talking about and let you know early next week . thanks again carl and god bless.. the oldman.........