Upgrade Help

from information i have gathered, with an automatic you'll wanna go with 4.10's instead of 3.73's. 3.73's are mostly for the people with 5-speeds. i think that gears and a t-lok would be an awesome upgrade to his car, it could hurt his gas mileage a bit if he does a lot of highway driving, but it will definately get him to launch off the line

3.73's

4.10's are the way to go with an auto. That's what I did, and aside from my punching it all the time, the gas milage difference is negligable. You may lose 1-2 mpg highway, but in city driving, you actually gain mpg due to the car shifting sooner to higher gears.

I also installed a TransGo shift kit and tranny cooler as well.

Check out the prices at GEFRacing.com and 50Resto.com. You might also want to replace the rear axle seals while you are at it. Only use Ford friction modifier, and make the switch to Mobile One Synthetic.

When I did the gears, I also went with a T-Lok, and love the heck out of it. It really does make a huge difference. If he plans to drive in the snow, then the T-Lok will help out a ton, but it isn't a replacement for snow tires.

Get the compltere install kit for the gears and T-Lok, your mechanic will be pleased with you.

The only issue you will have is that the speedo and odomter will be off. You can do one of two things after the gear install, pull the gauge pod apart and reset the speedo needle, or get a speedcal.

For the rpm power band on the V6 the 3.73's will be perfect!
I belive 3.73's would be a great choice! 4.10's would be better
for a V8 because you would be able to take advantage of them
better because the power band is larger! Good luck

when upgrading a 99-04 v6 mustang's rear end from the stock 3.27 gear ratio to 3.73 gear ratio you stang to shave off at most 2.5-3.0 tenths from your times. This is well worth the efford since most other bolt ons are lucky to net you a single tenth.

It is far better to buy and install a ford traction lock with the gears since the exact same amont of work goes into installing gears as installing a traction lock and gears. So that being dont let someone charge you double... basically when they sit the stock open differential down on the ground or tray to pick up the ring gear you slide the tlok diff in its place and thats really the only extra effort it takes.

www.gefracing.com has really good prices, make sure they are not out of stock, if they are or you just want to you can go to summit and order the stuff and they will price match with gefracing.com and may even give free shipping... so go that route.

It is a better idea to upgrade to an 8.8 rear end from a GT mustang (99-04 gt mustang 8.8 rear end is required UNLESS you dont mind running wheel spacers with a pre 99 8.8 rear end)

if you dont mind wheel spacers ( www.maximummotorsports.com has very good wheel spacers!) then go to www.speedconcepts.net and buy a comoplete ready to bolt up 8.8 rear end (minus axles which you can use from the stock 7.5 oem v6 rear end perfectly fine, they are the same ones used in the gt rear ends. )

the swap of axles is very easy and is all that is needed to put the 8.8 from speedconcepts.net into your car slap on the C clips from the 7.5 oem v6 rear end and the spacers and wheels and your done minus filling it with fluid and breaking them in.

If i had to do it over again I would go with an 8.8 in a SECOND, I have broke my rear once... I dont plan to again. The gears wont break .... the spider gears from the tlok unit or open differential will....

the 8.8 from speedconcepts is 725.00 ... which is about what you are looking to pay for 3.73 gears, tlok unit, and install prices. the 8.8 comes with 3.73 gears and a tlok and as listed above all you need is your stock axles and thats it.