Can anyone give me a rough estimate of how much I would gain in 1/4 mile time by going to 4.10s over the factory 3.27s.I have a stock 2000 gt that runs in low 14s my best being a 14.0

 

You should gain a few tenth's on your launch for sure but it is really up to the skill of the driver.

 

A buddy of mine hit 13.2 at 100 mph or so with 4.10's,K&N drop in filter,welded in mufflers,a custom tune,and e.t streets out back.

 

4:10s are too tall imo. But heck, they make 1st and 2nd in a fox feel mental

 

4:10's are nothing more than a good start IMHO. I am swapping to 4:30's this season and 4:56 next year when I go back to an auto tranny.

 

Not in a modular ford.
3.27's come stock,so 3.55's would be a waste.3.73's are "okey" if you plan on the power adder route,but for N/A,nothing less then a 4.10.
I kid you not,a stock 5.0L stang with 3.73's still feels way torquier then a modular stang with 4.10's LOL!

 

For an uneducated guess I will go 13.5

 

Just added 4:10's to my 05 this week but will have to wait till spring (when I can drive it) to really see how big of a smile this put's on my face! The short slow drive home from the shop gave me a taste of what to look forward too!

 

Don't fear the gear.

 

well depending on the first gear in your trans you might be making first gear pretty useless if you spin.i had a 3.65 first gear in my 4speed trans and a 5.43 gear out back with a 26 inch tall tire.i had to shift VERY FAST out of first but it didn't spin.in that case the gear helped.put it in you'll like it.just be sure you need it.4.10's suck on the hiway.you should hit 13.60-70's with the 4.10.