BeachStang04

No you dont need a new diff. if you get new gears.

Just put 4.10s in my buddies Gt (manual)two days ago and at 60 he cruises at about 2 grand...... and by no means is it overkill on the engine. So disregard what V6er told you.

akinahs

It might take a day or two for you to get an answer...but the people in this section are pretty helpful...someone will reply, but probably not tonight.

winner99

It doesnt matter... Whether 3's or 4's you dont need a whole new diff. Its easier and cheaper to have it done at once if you plan on getting a locker. You can buy gears and a lock for your 7.5.

mustangman02232

no v6er stang

you do not NEED to upgrade the diff on your car, but in stock form the v6s have a open differential, which puts power to both wheels till one wheel looses traction, then 100% of the cars power goes to that ONE wheel, so you leave one tire mark on the road, vs the 3.73s 4.10s will only have you turning 300 rpms higher or so and from stock you will loose probably 2 mpg on the highway and city will actually stay the same because you can spend more time in overdrive

upgradeing to a limited slip (ford trash-lok or a detroit or eaton unit) will allow power to be transfered to both wheels (leave 2 marks) and allows it to "slip" so you can turn better

a locker is similar to the limited slip but it doesnt let the wheels slip for different speeds arounds corners

and a spool will make both tires spin at the same speed (track use only pretty much)

caspers_mustang

Im suprised no one on here mentions about haveing to get your speedo recalib or the recalib gear.

l_shizzle_l

I drive with my speedo off, it's not that bad you just think you are always speeding.

skitso

so 4.10 and a t-lock sounds about what you would need

how much is my question

v6stang07

yea u dont have to have a locker but if u ever plan on getting one i would wait and have it all installed at once.