Finally was able to get around to getting my swap from 3.73 to 4.56 gears completed last week. It is definitely like a different truck. Doesn't feel like the truck is struggling to get out of its own way anymore. In town I have really noticed the improvement in acceleration and how much throttle I really have to use. On the highway, much less shifting out of overdrive to go up inclines.

Don't have any mileage numbers yet to report, but I think I am going to be fine there. Filled up Saturday night before heading to a club and ended up using 4x4 most of the way there because so much standing water due to heavy rain. Some areas had mud across the road. (All 2 lane rural highways in my area) Way home roads were clear so was 2wd then. Roughly 80 miles on the tank and used roughly 1/8 tank so far.

Quite happy with the improvement, but was hoping for a little more. Guess my next purchase will have to be a SCT and some custom tunes.

 

How much higher are your RPM's at highway speed?

What was your overall cost?

Want to do this so bad but the price is what's holding me back

 

Do you hear any gear noise?
Who installed them? did you do it yourself?

 

The rpm change is a simple ratio.
rpm afterwards/rpm before = gear ratio afterwards/gear ratio before
So rpm afterwards=(gear ratio afterwards/gear ratio before) x rpm before

 

Way to go- best decision and $1500 I poured into mine. It was a slug, now it pulls through gears quite nicely (aided by a canned tune) and is plenty good and capable now. I made the same jump, front and rear, with posi. I'm not smoking my 35's on the pavement, but prior to the swap I couldn't even break the tires loose on a gravel road! Talk about not being able to get out of it's own way! Now it's hard to not kick up dust.

Last month's elk hunt had me in some deep ruts and slick mud and I pulled through effortlessly in 2H and going from the Phoenix desert to high elevation was a breeze too. My tranny must be thanking me.

It was strange at first- felt just effortless, not blazing fast. With the cheap tune, it pulls- as I mentioned. Pulls real good.

Gratz!

 

I have nearly $1100 total in mine. I bought G2 gears online through Amazon, my cross pin shaft, Ford friction modifier, and diff fluid as well. I saved $100 over going with summit. My mechanic charged me $400 for the install and he also changed the oil while he had it in his shop. He is a Ford deal mechanic that works on the side at home and has worked on my vehicles for years. STX's do not have a tach, so RPM I couldn't tell you as I never thought to use my phone app to check. I remember awhile back using some online calculator that @ 60mph, I would be about 250 more rpm than if my truck were bone stock.

 

Sounds like a great deal and I'm sure many of us would like to have access to your mechanic!!

 

How do you know what gears to buy? I have a f150 2012 4x4 with a 3.73 rear axle 8.8, but I don't know how many splines is in it, can you help? I know I have to buy a 4.56 but thats it.