so if I understand this right the 4.10s are deliver more power or more acceleration correct ? but most recommend 3.73 for a daily driver and say its enough .

while looking at T-loks I came across this website http://store.chipsv6specialties.com/c75tr719.html

it says that the 4.10's are better for Auto (which I have/ V6) unless you plan on supercharging which I probably wont be doing atleast not for maybe 18 months or so .

I assume 4.10 better for performance specially for a auto and supercharging would negate the need for it ?

So for a v6 auto with a 7.5 rear end which would be better for me ?

And does 4.10 hurt the life of my engine ? not that 4.0's arent dirt cheap on ebay anyways and ford uses this same 4.0 engine in a bunch of stuff too right

 

3.73s' for automatic, 4.10 for standard. 4:10s' aren't suggested on cars with superchargers.
4.10s' do accelerate faster than 3.73s and 3.73s'get better gas mileage. Will it hurt your engine, well it might wear faster but it cost to go faster. Real race cars are raced and repaired and done all over again.

 

but what if you have the GT manual and you want to upgrade to the 3.73's? would this still get better gas mileage from the factory gears?

 

Man, I don't know. Only person here that has had 3.55s', 3.73s' and 4.10s' is bluestar.

 

No going to the taller gear will make your milage worse not better. It shouldnt hurt it much however. They recommend 4.10's for manual and 3.73's for auto because the two trannies are geared differently. I would go with 4.10 for a manual.

 

3.55 to 3.73 wouldnt be worth the change IMO....i went from 3.55 to 4.10 but really wanted more of a change even.

 

The taller the gear, the lower the number. Going from 3.55s to 3.73s is getting shorter gears, not taller. I cant speak from experience, but i would guess that city mileage would stay about the same and highway would drop 1-2 mpg.

 

I have an 8.8 with 3.73 T-Lock in my car ... I drove up the S.C. couple of weeks ago. Set Cruise control at 70 MPH ... Got 24 MPG ... RPM was approximately 2400 in 5th ...

In retrospect .. I could have went with a 3.55 and saved some $$$ since the 3.73 Take-off rear was more. The 3.55 would have kept me in boost longer in 1st gear ... and I may be able to trap on the 1/4 in 3rd .... There is no way I can do the 1/4 now without shifting to 4th.

 

but you have a GT and a manual at that . I have a V6 and a auto . sounds like I should go with the 3.73 I dont want to have to replace my engine until I hit atleast 120k miles

 

gears will not cause you to replace the engine, the way you drive the car will determine that

i missed the being auto part, yes 3.73 is what you should get