I have an 07 gt, manual trans, with k&n, magnaflow cat back and excalibrator tune, 3.55 rear end gears. 3.90 or 4.10 is my question, really don't know. Mostly worried about the usefulness of 1st gear and reving too high on the highway. I only drive about 2,500 miles a year with the car. Gas mileage is not a big concern. Any comments would be greatly appreciated.

 

4:10!
I have 4:10 and a S/C and I still have enough first gear. And honestly if your stuck between those two choices don't put too much thought into it because you really aren't going to feel any difference between the 3:90 & 4:10's

 

Thanks for the thoughts, do the higher rpms bother you at highway cruising speeds?

 

No not at all, there was only a couple hundred RPM's difference going from the 3.55's to the 4.10's. It's not that noticable.

 

My car has 390s, but with my reduced tire sidewall height they are effectively 410s. I drive my car on the highway and I rarely go above 80 when cruising because the RPMs are too high for my liking- Then I go back and drive my moms California Special with 3.55s and cruising on the highway is amazing, but the lower end grunt is definitely not present.

(Edit: For some reason I thought you were asking about a supercharged application)
Personally I think the best gear combo for a street driven supercharged car with be 3.73s or 3.90s at the most.

 

Seeing as how you don't have forced induction I'd say go 4:10's. If you ever get FI and it really bothers you that much you can always change it but for N/A you will love the 4:10's.

 

I would go with the 4.10 or if you plan on putting a supercharger 3.90s. We carry both so if you need a price let me know. I also have a set of 4.10 Ford Racing at the shop for $149.

 

4.10s all the way. I also went from 3.55s to 4.10s, and it wasnt as dramatic as I thought it would be, in a good way. I thought my fuel economy would plummit and the RPMs would jump significantly, but it wasnt nearly that bad.

 

Thanks everybody for all your feedback, the 4.10's it will be. To Derek@DRI, thanks for the offer, but I have already purchased my frpp 4.10's, before I even posted my question. Have a good day all.

 

You won't regret the 4:10s!

And choosing FRPP is a good choice. I have the same ones and they are quiet.

 

Thanks for the extra vote of confidence Fryguy. I'll be making an appointment on Monday to have them installed hopefully one day next week. Will let you all know how I make out.