DCzapla

Well a new rear end is on my to do list. Ive been told to o.ly get a 4.10 that its the only way to go. Im not racing the car its just a nice weekend car, and something i would drive on a shmmer vacation. With that maybe a 3.73 would give me a balance between better performance, and good driveability. Comments opinions.

CPTCO

I still love my 4.10s, even after supercharging. You probably have 3.55s now, so 3.73 would not be that big of a difference. 4.10s changed my fuel economy very little, the car cruises at 2500 RPMs @ 70. Just feels better passing, and overall it made my car more drivable.

Vivid Racing

This is kind of a toss up. It really is going to depend on what kind of driving you do. If you're going on road trips and wanting to get the best gas mileage on the freeway, the lower gear ratio would be the better option. Is there a reason why you want to do a gear change? What are you trying to accomplish?

breathegood

Some numbers to ponder assuming manual transmission. What is your goal? What RPM range do you most prefer to drive in? When you look at the numbers, I just can't see 4.10s making a huge mpg difference for highway cruising.

5th gear 2500rpm/3.55/84mph
5th gear 2500rpm/3.73/80mph
5th gear 2500rpm/3.90/76mph
5th gear 2500rpm/4.10/72mph

1st gear 6500rpm/4.10/38mph
2nd gear 6500rpm/4.10/64mph
3rd gear 6500rpm/4.10/97mph
4th gear 6500rpm/4.10/129mph
5th gear 6500rpm/4.10/189mph - theoretical assuming you have the HP to get there

Assuming stock tire size and manual transmission.

DCzapla

Its a 5 speed manual transmission. So maybe 4.10 wouldnt be so bad. Plus the driving around town i do tends to draw attention from lesser vehicles that want to test the pony. As itvstands right now the 3.55 does not get my car of the line at all!!

Vivid Racing

Have you thought about doing any power upgrades to help it get off the line faster, rather than changing ring and pinion? More power will help it get up and go, but keeping the rpm down at cruising speed to conserve fuel mileage. Catback exhaust and cold air intake would help a lot. Just presenting another option for you.

DCzapla

I have a ford racing bullitt CAI and a tune from brenspeed. Previous owner had UDPs on it as well, and he added some high flow cats along with a bassani axlee back

157dB

3.73s will make your 5th gear like your 4th gear is now with 3.31s.
4.11s will make your 5th gear like somewhere in between 3rd and fourth.

Vivid Racing

Well, in that case, if you've got the mods and still feel like it wont get out of the hole as fast as you would like, I would go with a 4.10. CPTCO is right. The difference between a 3.55 (providing that IS what you have in the vehicle) and a 3.73 is not going to be that noticeable. I was running a 3.73 gear in my 88' but I was right around 500hp, so it worked great. Good luck!

GTgeezer

Well I have 3.73 and as far as a DD like mine I feel a 4.10 might suffer a little on highway cruising unless staying under 60 is ok. I have a 5 speed so maybe much different if you have an auto. my 3.73 pulls very strong through all 4 gears. my 2c