Hey all i have a 5 speed 2005 GT i want to put some gears in it...but i have some concerns I want the car to be fast off the line either 4:30s or a 4:10 butI drive once a month to TN about 230 miles on the highway other than that road trip i stay around were i live what gearsdo you think would do me best. I dont want to hurt the car.

 

Go with some 4.10s. They won't hurt the car as long as they are installed properly.

 

The 4.10's will put you at 2,500rpms going 70 on the highway.

If you cruise at 80, your tack will be 3,000 [&:] Sorry, no info on the 4.30's.

 

I am going with 4.10s up til next summer...I really do need some more pick up til then because this
and a TC are really only gonna be the only mods I will have til FI.As it is right now I only have a CAI/tuner and though it's faster then stock it's still NOWHERE as fast as I want it to be..gears/TC will surely wake it up.

If you have the money for it I'd say use one gear for your needs right now and just swap them
out later.That's what I am gonna do~

There is this one member,I forgot his name but he swears by 4.30s.I remember him saying that he expects to be in the high 11s NA this summer,pretty sure it's also a DD as well.

 

RPMs in 5th Gear, Manual Transmission

Different rear gear ratios:

Speed

50 60 70 80 90 100

3.31 1,392 1,670 1,949 2,227 2,505 2,784

3.55 1,493 1,791 2,090 2,389 2,687 2,986

3.73 1,569 1,882 2,196 2,510 2,823 3,137

3.90 1,640 1,968 2,296 2,624 2,952 3,280

4.10 1,724 2,069 2,414 2,759 3,103 3,448

4.30 1,808 2,170 2,532 2,893 3,255 3,616

 

I had Classic Performance Repair (CPR) install my gears today. They mostly do work on older mustangs. It was the first time they did a gear install on an 05+mustang, but the have done gear install on 8.8 rear ends; nonetheless, they are meticulous and ensure everything is just right. I have not had a chance to really test the gears yet, but from what I can tell it will be an improvement. No gear whine to speak of. John's RPM/Gear post is correct. At 70 I am slighty under 2500 RPMS and at 80 I am almost at 2800 RPMs. My HWY MPG has dropped by 1-2. This moring driving about 85% hwy w/crusie control on at 75, I still managed to get about 23 MPG.

 

with my 4.30's i tach around 2200rpm at 55. i love them but i have tall wheels 275/35/20's. 4.10's wouldnt of been enough for me.factor in your wheel size also...........................

 

I have shorter wheels 245/45/17, so for me it's almost like running 4.30s.

 

50 60 70 80 90 100

Size 235/55 17 4.10 1,724 2,069 2,414 2,759 3,103 3,448
Diameter 27.18 4.30 1,808 2,170 2,532 2,893 3,255 3,616

Size 275/35 20 4.10 1,699 2,039 2,379 2,718 3,058 3,398
Diameter 27.58 4.30 1,782 2,138 2,495 2,851 3,207 3,564

Size 245/45 17 4.10 1,825 2,189 2,554 2,919 3,284 3,649
Diameter 25.68 4.30 1,914 2,296 2,679 3,062 3,444 3,827

 

I have 4.10's (about a month or two) Great mod, but you will lose about 3-4 mpg city driving, about 2-3 on hwy.