3.90 or 4.10 gears?
 

I am looking for a boost in acceleration for street use only. Car is C6 Z51 MN6. Any recommendations?? Not to worried about fuel mileage. Car will basically be stock except for K&N air intake and flomaster exhaust that came with the car.

You will get more spin at launch out of the 410's but also more speed post launch:thumbs:

How are you going to attach that increased effective power to the ground?

Welcome to the forum:thumbs:

What year is your C6? The 2005 has the weakest rear and the 2007 has fluid issues. As previously suggested traction will be a problem with the lower gearing. You can lower the rear tire pressure but that may not provide you much better traction.

Most importantly, you will also have consider the problem of tire shake or what we call wheel hop. I would suggest that you take the time to inspect the suspension and it may be a good idea to upgrade. It is better prevent wheel hop so that you do not destroy the rear if you just happen to dead hook the car.

You can utilize the search function for more information.

Good luck :cheers:

Sorry I forgot to mention it is a 2005...weakest rear does not sound good

The 67' 12bolt I had in my 72' Buick GS Stage 1 had 4:10 gears at 65mph on the highway it was going 3500rpm! that car got 5 miles a gallon (.030 over 455) unless you plan on drag racing a lot,I don't see the point in 4:10 gears on the street,say goodbye to your gas mileage too. IMHO

He did say he's not too worried about mpg with the gears. It seems the 3.91 would be the option to go with. There is also 3.73 as well but I don't know if it would be enough of a bump up to be worth it.

There is someone who made a post on here that shows (I think in teh C4 section) which gear ratios are fastest at what MPH. Not always does a steeper rear indicated better acceleration at every speed.

Put in 3.90s or 4.10s with some sticky tires though and hold on coming out of the hole. :)

With such tall 5th and 6th it wont hurt him that much. Instead of cruising around town in 2nd or 3rd put it in 4th. My friends 99 T/A with a 9" and 4.10s (though it has the .50 6th gear) with 450 to the tires still gets 20+ on the highway.

The 410 gear wil make the car pull like a freight train.. If ur gonna upgrade justgo straight to 410 you will need to beef up the rear end while your in there anyway. Also as some have mentioned , traction might be an issue so might want to think about some good tires, although little wheel spin is actually good for the rear end

:iagree::thumbs:

Go to this link and buy this ZO6 rear diff! For 2K you get a 3.42 gear and the ZO6 diff is much stronger than a factory unit, it also has a cooler. This is a great deal and you get the complete rear diff with axles and cradle. I paid more than this for just the center section when I installed a ZO6 rear diff.


http://houston.craigslist.org/pts/2972748499.html

What are the best tires to minimize wheel spin? They all seem to be rated A for traction.

For the street I like the Toyo TQ proxy drag radial the best out of all the different ones sold. My last set lasted 15k and I had about 10-12 passes at the drag strip also. For the strip I run Hoosier drag tires.

I have 4.10 gears in my 05 C6 (462 rwhp). I have 92,000 miles on the car and the rear is still holding. And you really can't compare a C6 with similar gears in a 72 Buick! I lost 2 mpg at most with the gear change, and I am running at about 1,700 rpm's at 65 mph. I do get some spin with the Invo's, and like Frank said, that's probably a good thing considering it's an 05 car, and I don't track the car.

So you did not beef up your rear end at all? just put in 4.10 gears? How much did it cost to do the mod?? This is what I was hoping to do..I wont track the car either

Had the ring & pinion installed for about $1,500. That's it. And I have about 50K on the rear since the gear swap with 120 hp over stock LS2.

However, it's a fact that the 05 differential case is weaker than 06 and up. So if I had it to do over again, I wouldn't put a ring & pinion in a 05 car. You save about 1K, but it can end up costing you more in the future.

Get the Chuck Cow tune and boost and forget about the gear change!!!!!!!!!!

I have already talked to Chuck and waiting for him to get home on Monday!!!

You can't just put a Z rear end in your car. You have to change the output shaft of the transmission among other things. You might want to do some more research before pulling the trigger.

I guess this thread got me to thinking about my modding madness during my C5 days... rule I thumb I learned to use was modding is normally a domino effect... once you change one thing, you have to swap 3 others :rofl: so OP, there is some good info in the thread thus far.. things to think about mainly are the other driveline parts....outputshafts, halfshafts, internal components of the rear-end

These cars are notorious for having the weak spot in the driveline.

If I were you, I would not go getting some crazy sticky tires, if you are going to drive on the street 90% of the time... if you do, I would beef up most of the driveline so you don't start breaking sht. I've seen it happen too many times here.

Spend a little more up front, do it right the first time vs.. spending a WHOLE lot more $$$$, time and frustration on the log run that could have been avoided