I think about installing 4.10 gears in my 07 GT automatic. Is there anybody with such a combination? What RPM you have when your drivin 60mph or 80 mph? Whats the V max? Thanks a lot?
Did you need more gas per milage now?

 

i am sure the gas mileage will suffer. i dont have experience with the gears, i am thinking about doing 3.73's in mine

 

I have 3.73's in my 07 GT automatic and at 75 my rpm's are at 2500 approx.

 

4.10's are a little overkill for an automatic. The TOP I would go would be 3.90's. But then again, Germany has some killer speed limits!

 

I know...but I'm no high speed racer...It's enough if the car goes 200km/h or 240 with max rpm...i wanna create a quatermile car with cruisin ambition (thats why i choose automatic)

 

Then go with 3.73's! You'll be very happy with it!

CR
Tillman Speed

 

i just had the 373's installed, they are awesome. I wouldnt go any higher in my opinion. As well as many respected tuners say not to go any higher than the 373's on an auto. But too each his own. I love them, get up and go even quicker. good luck

 

CR, what would you charge to change out the rear to 3.73?

 

I have 4.10's in my automatic. at 60mph I'm at about 2000 RPM, at 80mph I'm at about 3000RPM. On my trip from Louisiana and back (from Los Angeles) I averaged about 24mpg. Normally it would have been about 26mpg. In town went down a few mpg as well, but I have also done other things to the car at the same time, so I'm not sure what exactly changed the mpg, but I'm sure it's mostly the gears.

I'm not sure what v max is, so I can't answer that.

 

I've been running 4.10s with an auto trans since July 2005 (over 21,000 miles). And the last 10,000 miles has been with a KB supercharger. And I wouldn't trade them for any other gear ratio. IMO, they're perfect.

As far as speed vs rpm, use this spreadsheet to see what the difference are. Just plug in your tire size and gear ratio,




.

 

I charge between 350-375 for labor, and that's completely set up with gear oil and limited slip additive included. Sometimes I get guys that specifically ask for the Royal Purple gear oil which is GL4 and 5 and I charge an extra 20 for that. The gears themselves I can get Ford racing, among others. It depends on what brand. I stock the 3.73 & 4.10's and install kits now that they've grown so popular. Give me a call if you're interested and I can give you an exact quote! THANKS

CR
Tillman Speed

 

Well I am not a racer yet, so I think the 4.10's are too steep for the street car, sometimes strip car. Obviously for the serious racer, the 4.10's and 4.30's seem to be the gears of choice. I personally dont want any higher rpms for my highway driving. But like I said to each his own. Lidio from alternative auto supposedly wont even give you a tune on an auto with 4.10's but that is what I have read here, not from personal experience. Most suggestions I have heard are the 4.10 for the manuals, and 3.73's for the auto's. It just depends on what your into, and how much highway driving etc. I am sure I would have loved the 4.10's too, but I am more than satisfied with the 373's. Don you have put a lot of money into your car, so I am sure it is awesome. I too in the future may go with a kenne bell sc. Need some more cash, LOL. Later all

 

Supercharger/Turbo/Nitrous is the only way I'd go 4.10's on an Auto. There's no need for a 4.10 unless you have the power to move through those gears more quickly. We've tuned quite a few autos with 3.90's, though. 90% of Auto's we've tuned have been 3.73's or 3.55's.

CR
Tillman Speed

 

Lidio gave me a tune for my auto with 4.10 gears, night and day difference over stock.

 

Does the desireablilty of either the 3.73 or 4.10 change with a manual trannie?

Tillmanspeed, How much is the parts and can any good mechanic to the swop? Do you recommend anyone in the Chicago - Milwaukee area?

 

Parts should roughly be $260 and install should roughly be $350, so it should be like $600ish. That's gears, install kit, installed with Royal purple from our shop... I don't know too many people out in Miluakee. Can anyone help Jamo here?

CR
Tillman Speed

 

Does anyone know any good installers in the Cleveland, OH area? I too am looking to get some 4.10's for my 06 GT 5spd.

 

Speed, Inc. in Schamburg, IL

 

Hey CR I am looking to put 3.73s in my auto with Roush Supercharger. I have allready set things up with Roush and they will retune my pcm with the 3.73s in mind.
What kind of prices do you have on the Ford Racing 373s? I was hoping to have them installed before going to FFW next weekend but wont be able to. I was just going to buy the 373s there if they were a good price.
Also my installer said it would be a good idea to purchase the install kit as well just in case and to make things easier.
Also would you recommend Royal Purple? vbmenu_register("postmenu_851601", true);

 

I would reccomend royal purple, for sure! I can give you a deal on the install kit, gear oil, and FRPP 3.73's for under $300 dollars. Probably around 290 to the door. I can do Motive Gears, which are very good quality, and more affordable. I've never had any problems with motive gears, and we run them in a track car. They're like 245-250 shipped, so it could save you a little money. Let me know if you're interested!

CR
Tillman Speed