Murdered07

I have the whole car torn down to install a new clutch and while it's out was thinking about changing the gears, Iv heard a z51 model effects this with the difference in the gears from a base model but who has a 410 in a z51 or even a base and could say it's worth it to change, my car makes roughly 450 now as a cam only if that would apply to anything

Paratrooper307

I put 4.10s in my 05 z51 when I had it. I was changing the gears anyway, so it was worth it to me. It was a little snappier on the street and of course had higher revs on highway trips, but not a night-and-day difference.

I guess it depends on your intended use. For a street car it was enjoyable but probably not an expense I would have taken on if I wasn't buying a diff anyway. Side note: If you see FI in your future you might want to stick with stock gears, as numerically lower gears will load the engine and build boost better, and prevent you from blowing off the tires as easily. I'm sure others will chime in with their reasoning. You'll find proponents for both.

Red Devil Z51

Lets face the truth 4:10 4:11 4:33 4:56 4:88 5:13 gearing is basically for drag racing reason being the rpm's on the higher numeric ratio's will make it very impractical for any kind of trip on the highway. Around town you can live with any of these. But gas mileage will drop out the bottom the higher # gear you use.

evo8act

I'm boosted with 650 plus whp, I have 390 gears along with z51 trans and love it. Street tires are useless but with my toyo r888s and properly setup suspension I hook well and it's a blast on the street.

Suns_PSD

I have an "08 Z51 w/ 500 whp and 4.10s and its freakin perfect. Do it!

LJD51

I had 4.10s in my '05 base coupe for 77K miles and could not have been happier...loved the increased ummph and only suffered a 2 MPG loss in average MPG...when cruising on the highway at 70-75, RPMs with stock 3.42s was 1,500-1,800 and the 4.10s was 2,000.

I know the gearing in the Z51 trans is different and RPMs/average MPGs will be different than a base trans but 4.10s coupled with a current generation MGW shifter and lower box will put a big on your face.

If you can find someone near you that has 4.10s, take a ride...then make your decision...

JMHO...

Boomer111

Not in my experience,

I do have the base with 4:10's.

Driving at 75 mph around 2000 rpm isn't impractical.

I still see over 25 mpg when averaging 72 mph on a 600 mile road trip.

This trip included over 100 mph driving for a few hours in Nevada at 4 am.

Averaging 72 mph with numerous stops is moving along for a 600 mile road trip with the wife.

Best mod I have done.

I didn't buy the vette for fuel mileage although it is a nice perk comparatively speaking.

What makes the lower consumption is just what is behind wanting the gear change.

Murdered07

is there anything else needed to do this install or can I strictly get the new gear and switch them out and be done?

Dano523

Guessing this a strip kind of this, since on a High speed road coarse, very seldom will I even be in 2 gear or lower in a z51 car instead.

Truth is, if you are trying to close the gap on a street car gearing to get it lower for a few gears, would be better to just re-gear the trans, and still have a OEM OD 6th gear for fuel economy when needed isntead.

Hence the z51 trans is already lower geared for the first few gears from the start, and it does not catch back up to the standard trans gearing until the final gear instead.

So on a z51 trans, it would be the other way around if you are going to gear the diff higher, and it would the first few gears in the trans that you would want to gear up higher instead (back to a M-6 trans). Hence from a dead stop, the z51 trans first gear is already high enough with the stock diff gearing, and if where to gear the rear higher, would need to gear the first gear lower instead to make it usable (or just not use it).


Lastly, in stock dressing and stock'ish HP, the top speed on a z51 is just shy of 200mph. Hence although the car is geared to get you to around 226mph, its the wind at 200mph that is obstacle isntead. Again, the 6th gear on the trans is more of an OD, then a extension spacing of the gears from 1 to 5, and if the game plan is to be able to rev the car out to 200mph, then gearing the trans for the 6 gears to be sequential instead of an OD, would be a wise invest instead.

Hence the car will pull clean to red line in 5th (about 175mph), then reduce the gearing in the trans across the board and not have 6th geared at a OD, then will be able to cleanly pull to red line in 6th to the 200mph instead.

Lastly, for strip use, the manual trans is a obstacle, instead of a god send instead. The reason, you can not shift a standard trans as fast as an auto trans can, and if you are lowering the gears and adding in more shift changes down the strip, your just making your slip tickets longer isntead.

So lets break down a stock z51,

0-60 take just under 4 seconds,
1/4 mile is right around 12 seconds.
At the one mile mark, your around 160mph.
At the mile and half mark, your pretty much rung the car out, and just shy of 200mps.
With the great brakes on the car, at the half mile mark and full on the brakes, the car is back to 0mph by the 2 mile mark.