3.08s to 3.73s or 4.11s

[HIM]

When I eventually bag my truck I wanna put new gears in the rear end. I have 3.08s and they suck ass so Im thinkin of puttin in 3.73s or 4.11s. How hard is it to put new gears in? Would it be easier to just find a s10 with the gear ratio I want in it and swap the entire rear end out or just change the gears?

[ZR1-S10]

Go with a set of 3.73, there still give you some revs to play with on the highway. Changing gears isn't hard it just takes a long time due to the backlash and preload having to be dead on correct.

[Sparky2263]

I wish I still had my 4.10's in. Difference at 70 mph was only 3-400 rpm's but it lost me .3 in the 1/4. Didn't change my town mileage and only gained .5 mpg on the highway.

Anybody wanna set of 3.73's good used? ;)

[Supercharged-ZQ8]

3.73s, definitely. . . I had 3.08s until a couple days ago -- installed 3.73s. I haven't really gotten into it yet (alignment issues from suspension upgrades, and wanting to break in the gears properly), but I notice a difference even driving conservatively.

Have you ever done a gear swap before? If so, the same applies for this. If not, have a shop that you trust do it -- a slight bit off in the spacing and you either have serious noise or a improperly worn teeth that will eventually fail.

[HIM]

One of my friends did his own and it turned out good and I dont think he knows his ass from a hole in the ground as far as that stuff goes. Ill probably have a local shop put them in just cuz its easier and they know what they are doin.

[nomaboy]

4.10 or 4.11 are the way to go. I have absolutly no regrets concerning gas mileage or rpms on the highway. the small loss comes with big gains. I had 3.42 and switched to 4.10 and gained .5 sec in the 1/4.

[DROPPEDGMC]

4.10's imo:D

[OBI WAN]

If you have a manual, forget 4.10's, you wont have a first gear unless you run 30 inch tall tires. But that isnt a bad thing since per rev you'll go father faster, but thats a whole different story the S guys never understand!

[HIM]

I have a auto trans. I dont really give a rats ass about gas mileage. I gotta put gas in anyways so why ***** about it. *****ing doesnt fix anything. I just wanna have my truck run as fast as it can for a daily driver and be reliable so im kinda stuck on what gears I should get. Im thinking 3.73s especially cuz I wanna s/c it one day and I think 4.10s with a s/c would get horrible traction ,not that 3.73s would be much better, out of the hole but at least I wouldnt be running in boost levels on the highway because I have such low gears. But is it pretty easy to change the gears. Ive heard its easier to just buy a whole new rear axle with the gears already in them and swap them out.

[nomaboy]

unless you know what you are doing with measuring backlash and pinion seat don't attemp to do it your self. if your measurments or gear set up is just a little off you will be replacing the gears real soon.
If you never have done it before take it somewhere.

[ZR1-S10]

You could try and find a 8.5" rear with 3.42's from an SS and swap that in. You won't get all the gear you want but the stronger rear would be nice (e.g. S/C).

[crazy91s10]

3.73s did wonders for my 2.8/5spd and i didnt lose much if any top end. and i get better gas mileage cruisin in 5th. when i had my 3.42s id always be shifting between 4th and 5th to get speed on the highway killing my gas mileage.


i'd say go for 3.73s if your lookin for economic daily driving acceleration. go for 4.10s or 4.11s if your lookin for quicker track times or you just dont care what your top end is on the highway.

just my experience. good luck with it.

[OBI WAN]

I have a auto trans. I dont really give a rats ass about gas mileage. I gotta put gas in anyways so why ***** about it. *****ing doesnt fix anything. I just wanna have my truck run as fast as it can for a daily driver and be reliable so im kinda stuck on what gears I should get. Im thinking 3.73s especially cuz I wanna s/c it one day and I think 4.10s with a s/c would get horrible traction ,not that 3.73s would be much better, out of the hole but at least I wouldnt be running in boost levels on the highway because I have such low gears. But is it pretty easy to change the gears. Ive heard its easier to just buy a whole new rear axle with the gears already in them and swap them out.

OK' I'll go a step further! You dont want 4.10's with a S/C because of traction. You want all you can get speed wise etc.

Now if it was ME, I'd run the 4.10's and bump up the tire diameter to 2- 2 1/2 inches over what you currently have. Every inch changes the final drive ratio, which is where RPMS and gas milage come into play roughly .18. Going 2 - 2 1/2 taller makes a 4.10 act like a set of 3.74's for rpms and gas mileage.

A 27 inch tall tire is 84.82 in circumference- 7.07 feet- 186 tire revs per 1/4 mile
A 29 inch tall tire is 91.10 in circumference- 7.59 feet- 174 tire revs per 1/4 mile

Thats 12.4 revs per second at a 15.0 1/4 time
Anybody want to finish the math. Mass weight and acceration plays a factor of 60%.
Taller tire means, higher sidewall
Higher side wall ,means a wider foor print per aspect ratio
Wider footprint per aspect ratio means better traction
Also per every inch wider a tire is you can drop air pressure 4 PSI and maintain the same weight carry.
Lower air pressure to maintain the same weight carry compresses the tire further upon initial acceleration which leads to more traction!

Anybody know where this is leading???

[blazen]

also isnt it true that if you have all your power in a high rpm than a shorted gear will do you better but if you make good torque at a lower rpm than a longer gear ratio will be better because you'll get to use your torque curve more to your advantage. i'm not sure if this is true its just something i've heard

[Sparky2263]

Consideration of gear choice includes dyno results, tire size, stall speed (if auto) and intended use/desired operation.

Most guys run nowhere near enough stall on the 4.3's so the 4.10's aren't a bad choice of gear. Drawback is a slight loss of interstate mileage.

Torque curve peak is far enough up you ain't gonna pass it as far as 4.10's go. As far as losing torque past 3500, that's not the issue. Horsepower is. Yes, it is a derivative of torque, but a VERY useful measurement nonetheless. You want to shift a little past peak HP and land right in the meat of the torque curve. This produces the fastest acceleration.

Try telling a professional engine builder horsepower doesn't matter because it's just a computation from torque. hehe

[Maximus]

I was gonna install the 4.10 gears I have here but with focking gas as high as it is right now ever little bit helps.So the 3.73's will be staying for right now.DAMN OPEC ASSHOLES!!

[ZR1-S10]

Screw the gas! It's not that high, people just like to *****. A gallon of beer costs more!

[Sparky2263]

Gas during the 1973 arab oil embargo was the equivalent of $5 per gallon in todays dollars. Same deal with gas during Carters screwing around in the late 70's. We still have cheaper gas than %98 of the whole world.

It's cheaper in the middle east but try getting the average American to ride a camel.

:o

[HIM]

See this is my real problem with gear selection. I wanna in time bag my truck but till that day I wanna be able to beat my best friends 95 5.0 mustang (94-95 were ****ty years for the 5.0 mustang. They only made 210 horse). He doesnt know what egars he has in it but I raced him in my 99 4.3 auto x cab with 3.08s in it and I held with him till about 80 mph and he started pullin so Im guessin he has some mickey mouse bull**** highway gears like 2.73s or something. Im just looking for something to be able to beat him till I can afford bags then im goin performance wise. Mayne an s/c. I dont really do a whole lot of highway driving and I dont really give a **** about gas mileage so Im just looking for something to get me faster than his 5.0 for the time being.

[snoma]

If you don't know how to change them yes it would be easier to swap axles. But it'd be easier and chearper to pey someone to just swap the gears. Also consider having all your bearings changed depending on how many miles you have, while it's apart.

[HIM]

I have 80k on the odometer. I wanna put 4.11 or 4.10s in but I really want both tires to hook up instead of the one wheel wonder I have going right now. If I just get the gears changed with that solve my one wheel burnout woes?

[ZR1-S10]

Nope you need a LSD to hook up both tires. SLP has a kit that has your choice of gears, a Zexel diff, and a new cover. It's what I used to upgrade my rear. The kit is $800.

[Maximus]

Screw the gas! It's not that high, people just like to *****. A gallon of beer costs more!When my daily driver starts cutting in to my monthly expenses more and more I find it hard to just say screw it.I don't care how high it was in the 80's or why it was.When something sucks it sucks no matter what the year is lol.That said I am still thinking of installing the 4.10 gears to help keep my truck in it's mid power sweet spot.And though going to 3.73's from a 3.42 made a good improvement on my truck it's just not as much as you would think.Now going to a 4.10 from a 3.42 is a big differnce.And if gas mileage isn't a big concern for you I would damn sure choose the 4.10 gear.

[Hammer]

how would the 4.10's work with a T-56 :)

[Sparky2263]

how would the 4.10's work with a T-56 :)

Like crap. 5 speed is a whole different story. My experience is 1/4 mile so I'll share that.

88 Mustang GT 5-speed. Stock 2.73's (WHY?!?). Had a VERY hard time coming outta the hole. Either spun like crazy, bogged or I made the clutch smell bad. Bad smelling clutch was quickest 60' time folowed by bogging it. Well, heck, I'll throw some 3.73's in it, right? UGH. First gear practically useless and replaced the synchro's after crashing 2nd so many times. Also had to shift to 4th before the stripe resulting in the loss of ET there (I ain't a big fan of buying synchro's over and over). Tried 3.42's and if I wound the motor REAL tight I could cross the stripe in 3rd. Said screw it and put some 3.23's in. Perfect. Slight bog at the hit, didn't have to crash 2nd too hard and crossed the stripe comfortably in 3rd.

2.73 ET best~ 14.8
3.73 ET best~ 'bout the same (ain't that crazy?)
3.42 ET best~ 14.3
3.23 ET best~ 14.2

Slow for a GT? Nope. Bone stock motor with my usual tricks thrown at it.

2 other experiences with 5 speeds. Results practically the same.

[Maximus]

He's talking about the T56 six speed and they are great in my opinion.I have some traction problems but no more than my last Z28 six speed with the stock 3.23's.They really help get me in my peak HP quik.And when shifting im still in a good area of the torque curve.I also use a larger tire at the track that reduces my tire spin.And you will still have plenty of top end speed with sixth gear.Of course a 4.3 isn't gonna respond the same as a LS1 so that will play out different.You might be better served to use 3.73's with a 4.3.It all depends on your setup.

[Sparky2263]

True. The Mustang had 26" tires. Had it been 28's the 3.42's would've stayed. Come to think of it, they weren't 3.42's, they were 3.55's.

Oh well.

[joker2040]

I'm still debating 4.10's.... They would be ok for me running n/a but when I start to spray all hell would break loose.

[Sparky2263]

With the 4.10's and a 26" slick I crossed the stripe at a somewhat uncomfortable 5700. The 28" slick made it much better. On a 12 sec. nitrous pass ;)

[HIM]

I wanted to originally get a s/c so I figured on getting 3.73s but since then Ive realized that a s/c is a little bit above my price range I might as well go with the 4.10s and maybe some internals (like a cam and some roller rocker arms or something along those lines) instead of forced induction. I figured with the 4.10s and a s/c 1st and 2nd gear would be a void and would only be good for burnouts not really speed.

[lyonsfam1]

ok so i have an 02 xtreme 4.3 5spd with 3.08 gears with a S/C. i drive 50 miles roundtrip highway to work during the week and my mileage when im "good" isnt that bad but i want some more speed when im at the track. what gearing would be a good compromise for me 3.73? i know pretty much nothing about gearing except the basics.


by the way my best run was 15.02@92.28mph on street tires @ 2700ft i believe.

[Hammer]

actually i think that if you have a short enough gear like a 4.10 or even shorter like a 4.50 you won't be as apt to spin the tires.... sounds weird but we had a dump truck with granny low and you'd spin the tires in 1st but granny low it was such a short gear you ran out before it would spin. i mean it was a short gear but you got moving wicked quick. that is more shifting but if you can do it with short throws and limited clutch movement you can be very quick with short gears and not spin the tires cause of the rpm limit per gear. you won't have much top end though but 4th gear would scream you over the line.... thats my guess at it.

basically the shorter gear gets you into the power band quicker but moves you a shorter distance after you have maxed out the rpms.

[Sparky2263]

If I was recommending a set of gears for an s/c application, I'd say 3.42 or 3.73. Reason is the torque curve is much broader with a s/c. Don't need the 4.10 advantage to get you into the torque band like the n/a V-6's.

I just put 4.10's in our n/a 383 Monte Carlo SS. Massive torque curve, spins to about 65-6700 and runs high 10's.

On the other hand, the 454 Chevelle has run fastest with 5.13's. Why? Short torque curve because I'm rpm limited (5200 and the game is over). Runs mid 12's.

[Hammer Head]

3.73 or 4.11's depend on a number of things... hp & torque curves.. how hard you want to launch, assuming you can hook up.. what trans you have... etc, etc. I've been planning a 6.0 iron block swap since I bought my s10 & i feel w/ the Z06 corvette cam & at least the 4L60-E trans behind it.. a 4.10 is the way to go, but then again, that's just me.

[loas]

I'm curious. I have been looking for a post about a t-56 with a 4.3. I saw on the last page a mention, but I want to know if it was on a 4.3 and if so, what was involed. I have seen a how-to for auto to manual swap, but no swaps with a t-56. any help?

[Hammer Head]

Welcome to the Planet. http://www.s10planet.com/forum/showthread.php?p=63185#post63185 That should help you out.

[MadneSS-10]

I know 4.11's woke my monte up, I have a hard time not breaking them loose. lol

[Diesel_Cain2000]

I went to 4.11s with a posi locker in it. Your best bet is just to find a rear end with them already in and just change the whole rear end. Thats your cheapest, fastest, and safest bet right there. I havent noticed any big losses in gas mileage but I have noticed it runs faster. And I wont get stuck as easy with the locker in there.

[Hammer Head]

Well seeing as how about four months have passed, budget isn't there for me to get 4.10's but I just pulled apart some of another rear from an Xtreme last night that I was told had 3.73's in it. That should be more than plenty. It should hook well enough w/ those gears & the traction bars so I'm not just sitting there having my own little burnout show.