Last week I got my gears in, how much do you think they lowered my 1/4 mile time? Ill be going back to the track in 2 weeks, make a guess.

EDIT: Another update, I checked my city MPG, and i got 14, which includes a pretty heavy foot, and before i got 10, and sometimes 12 at the best light footing it.

 

Allright my guess is aroud 1/4 sec.
How much better does it feel now and did ya get that vid yet?
You had 3.55 gears right?

 

My guess is close to Kevin's guess...about 0.2 second...

 

Right now, with my big tires on, hot and humid, street tune, and not that good of gas, it runs better than on a cool night, drag tune, with my slicks, and 94 octane with my old gears. Yea i had 3.55's

 

Just got mine in too and had 3.55's. I'm in the break in period, so I haven't been able to really romp on it, but you can tell a difference.

 

Just curious to know what the price for something like this run's! Im in the process of getting my money together right now to make this upgrade.

What's involved during the break-in period? How long is the break in period?

I was quoted just under 600.00 Parts,Labor.

3.55 to a 4.10, thinking about getting them to go ahead while they are in ther rear diff. housing to go ahead bit the bullet and get a LS upgrade as well

Thanks!

 

good idea there. I got mine from ford racing, gears and install kit for $300. BUT that was one heck of a deal.

 

I got mine from Accuautoparts

Precision Gears are what I went with, with master install kit and 2 rear axle seals + bearings. Cost me ~ $350-370 shipped.

Labor was $325 + oil and additive bumped me to $370ish.

The break in period for my gears was: drive 15-20 miles to get the differential to normal operating temp. Let the truck sit and cool completely. Drive 200 gentle miles. No towing. If you are towing, an additional 300 I think was stated before you can start doing so.

After a good 1000 miles or so, I'm going to take it back and get it drained and re-filled again.

Hope this helps.

 

WOW !!! Significant jump on mpg's, I find that hard to believe replacing only the gears would give you that kind of boost in mpgs" and NO, I am not calling anyone a liar, I am just surprised on the stats"
Hmmm I have 3:55LS gears on my Screw, if this increase is accurate, I might save up for an upgrade like that.

What are the pros/cons in doing this from 3:55LS to 4:10's?

2002 Screw
5.4L
285/60/18

 

How did you get the two small pinion gears in place I cant get mine back in

 

Did you recalibrate your speedo?

 

No, but I checked it with a gps and im within 3mph, and i doubt the gps is 100% accurate

 

Built,

A little off topic, but before you had your custom tune, did you run the throttle body? Was their a nice increase in HP? Was your A/F a little off without the tune? I'm thinking of getting an aftermarket TB but am afraid of running too lean. Im also adding a blower in the near future. Whats your take?

And how about the Jusnes Fans? Happy with those as well?

Thanks.

Joe

 

I Love my fans, could not be better. The throttle body was on my truck when the engine only had a superchip, intake and exhaust. It did not run much different, but it took off faster from a dead stop, more responsive. with what I have now done, Im sure it helps out a lot. I would not worry about running lean from it.

 

If you went from 3.55 to 4.10, and didn't recallibrate your speedo, then your MPG change isn't accurate.

Your gear ratio change is about 15%...and your reported MPG "increase" is about 20%.
So in reality, methinks you're getting about the same MPG, but with far better performance, with the 4.10s.