A buddy of mine HAD a 98 Z 6 speed with 4.56's in it. With just those gears and a cheap Street Sweeper muffler he ran 8.5x's in the 1/8th...on street tires That thing was MEAN!! They lasted about 6 months or so I think. But definatly NOT what you would want if you drove it very far every day....I think he got like 160 miles to the tank.

 

4.11's rock!, with the 6spd you can't beat that overdrive gear.

 

Wow, some misinformation in this thread!

94+ M6 6th gear is .5 ratio. With 4.10 rear and 285/40/17 (assuming the tire diameter actually measures out to the calculated 25.97"):

70MPH = 1857 RPM

Saying "4.10's" is the only way to go, or "4.56's would be the ultimate track gearing" or "it's stupid to do 3.73's" again isn't correct for a lot of people.

Let's talk some gears. This is all assuming you have a decent rear end (12-bolt, 9", etc.)...IMO, don't dump money into the stock 10-bolt, at least for us M6 folks. Let's not forget, you want to go through the traps at about the top of 4th gear, which is a 1:1 ratio. Let's also remember anything above a 28" tall tire is getting to be a PITA to fit, and 26 and especially 28" tall tires are the easy to come by, common sizes. Stock tire diameter is 25.66"

4.56's. Great for a heads/cam car that can rev out pretty high. With a 26" tall tire (say a 26x11.5x16 ET Street, pretty common tire and a good match for this setup, and is 26.2"), at 6800 you'll be at 116.28 MPH. Very good gear for that. Stepping up to a 28" tall tire, you'll see 124.26....marginal at best for a heads/high reving cam and nitrous car.

4.10's. Great for a heads/cam car with a smaller cam that just can't rev overly high, like a Hot Cam. Those same 26" ET Streets, at say 6400 RPM, are good for 121.7MPH. Add a power adder on that same cam, better hit the 28" tall tire for 130, which works pretty well. 26" tall tire works well with this gear and a high reving cam.

BUT this is a crappy gear for stock rev-limited cars running a power adder. 5800 RPM on that 26" tire is only 110MPH; 117.88 on a 28" tall tire, which is also very marginal. Run a stock diameter tire (like a drag radial), and you are only good for 108MPH....which starts getting marginal if you are stuck with the stock cam....you really won't want to add a power adder (even a small shot of nitrous) without moving up to a taller tire. This is good proof that 4.10's are not good for everyone.

3.73's. Stock rev-limit gear of choice w/ a power adder. 5800 RPM w/ a stock size tire is 118.75 MPH, which is plenty. 26" = 121. Sadly, I went with 3.73's when I was internally stock, running my 26" tall ET Streets. It was an AWSOME choice of gears back then for on the juice; 4.10's would kinda sucked for me. But now that I can rev my car out, they are fawking me, especially when running N/A. I'm either forced to rev her to 6900-7000 at the top of 3rd through the traps, or drop to 4th gear early and not really getting to use 4th. So far, I've chosen just to rev her out. Once I can afford a nice bottom end and direct port, this gear may prove to be better than 4.10's IF I decide to stay with 26" tall tires.

As you can see by this post, no one gear choice is good for everyone. And people love to forget the tire diameter and how high the car revs out, which is just as important in the gear argument as the gears themselves. Let's not forget that these calculations don't take into account tire growth on the big end.

Calculations: MPH = (RPM x tire diameter) / (rear gear x tranny gear x 336)

Tire diameter (in inches) = ((section width x aspect ratio (in a percentage, so 40 would be .4) x 2) / 25.4) + rim (inner tire)diameter

 

ttt, I didn't post all of that for it to just go to waste!

 

I think you silenced everyone -- lol

 

Thanks for all the replies. But now i am kinda confused on whether to get 4.10s or 4.11s? Which ones are stonger? Which ones make you go faster? hahahaha Thanks again

 

oops i have 4.11's in my moser axle. 4.10's is the common size for 10 bolts

 

4.10s are for 10 and 12 bolts, 4.11 is what it is in for 8.8 and 9 inch ....right?

either way great knowledge u dropped Brodman...

i wouldnt trust any higher than 3.73 is our garbage 10 bolts tho, i broke the rear with stock 3.42, goin to 4.10s makes them too small and weak in a 10 bolt

 

Something EVERYONE is forgetting is that this guy has a stock 10 bolt right? The steeper the gear the more you are shifting and the more stress there is on the gears. That alone makes them more prone to failure (inherent weakness or lack thereof aside).

Joe

My personal choice with my new 12 bolt is 3.73....I liked them the most.