3.73 will have a noticible increase, 4.10s a hair more (on an auto, manuals may see a loss due to traction issues).

Top speed will not be affected either way unless you're tuned to remove the limiter settings, even then, there is no reason to push your car to it's top end.

 

So you think the 4.10's are better because I dont plan on really hitting 120 I'm fine with 110 if its that much quicker off the line?

 

And how much will it cost to get installed or how hard is it to do a home?

 

what saftey mods do you have done to be driving such fast speeds?

i was quoted $300 from a local place

 

I don't drive that fast I mean I have hit 110 once or twice but I was just curious if it was going to slow my car down alot from like 80 on with all high end speeds.

 

Do you know how much it might cost to have installed?

 

Shop around you might find a deal. But it typically costs $200-$400 for installation. Unless you're really confident and know what you're doing, I'd recommend taking it to a professional and have the gears installed. The fact that you're asking if it can be done at home means that you should definitely take it to a professional.

If you have a manual then 3.73, automatic 4.10.
Also, you might want to just opt out for an 8.8 rear end all together (better, stronger.) And have the gears of your choice installed before swapping it in place of the 7.5. The price on those range from $400-$800. Search around, I've seen these for sale for as low as $200, but that's very rare. MPSausalvage has them for sale all the time. Check their ebay store or give them a call.

Oh, and I wouldn't worry much about the top speed with the gears if I were you.

 

a 7.5 with a detroit true trac or eaton LSD will be stronger then an 8.8 with a trash-lok

 

Well you will notice a HUGE difference from stock gearing to 3.73

Prices vary on where you live. To be safe id say 300-500 dollars.

Once you get those gears in, going fast isnt fun anymore...bumping through gears is.

And asking about driving 110 isnt cool anyway man haha.

 

Do a little more research, gears are something you need to really consdier before you buy, because they will have a drastic affect on your driving style, conditions, and abilities.

In short, the steeper the gear setting the harder your car is to control off the line (rather that be normal driving from a stop light, or aggressive track driving), a steeper gear will make 1rst and even 2nd gear harder to control, especially if rain, snow, or ice is added into the picture. I have 3.55s (maybe 3.73s, as that's what my personal wheel test showed, will try again in the future with a buddy to confirm) in the GT and it's a pain controling the car in a turn on rainy conditions, very easy to spin out and I'm barely giving the car gas, just did so a couple of days ago.

Another thing is your car will opperate at a higher RPM all the time when in gear. This means that you'll burn more gas (unless the steeper gear puts you in the "sweet spot" where your car burns less gas). The upside is you'll have better accelleration potential, but at what cost to your wallet.

In short, if you're putting gears on a DD, reguardless of tranny, I say 3.73s or lower, if you're building a track strip car, then 3.73s or 4.10s will be your main go, building an autocross car, then you may want to look into 4.10s minimal.