Full Throttle 5.0

Many years ago in my hot rodding days, it's was a fairly simple task for a competent mechanic to change out the gears on a rear axle. Is this still the case. Wondering what it would cost to upgrade to the 3.73s from the 3.31s.

pb65stang

It's much more expensive to have the gears changed after the fact than it is to just order them from the factory. I just put a new ring & pinion in my Mustang, and it was around $1200 when it was all said and done. For the $400 the factory charges, it's much easier to go that route.

I would agree with above, if you're going to lift/level, add tires, and tow a bunch, 3.73s are the right choice.

roadPilot

Depends on how high you're going to lift, how much heavier the tires & wheels are, and how much you're going to tow. In many cases, the 3.55 is the perfect "middle ground" between MPG and low-end torque.

pb65stang

I don't disagree, hence why I went 3.55. But if he felt an Eco w/ 3.31 felt sluggish with his trailer, a 5.0 with 3.55, plus larger tires, will probably also feel slow to him when pulling.

rkfvd3

I had a front end issue with my truck about 15k and has never been fixed. It feels like it's always under a load and runs pretty horrible. As soon as it happened my mpgs tanked ( I average 12 now in a 13 platty with the ecoboost) and I had a puddle of fluid from the front end in my driveway. Everytime i take it in they act like I'm crazy even tho the service manager has heard the grinding in person and said it was a heat shield rattling. Then the horrible fuel mileage is from "winter blend" gas that apparently kc has year round. Plus it still makes random grinding noises from the front end and can't ever seem to get it fixed so it's gotta go. My 5.4 had the 3.55 gears and it seemed fine with bigger tires and pulling a much heavier trailer than I will now. I kinda went on a rant there but I really hope the 5.0 with the 3.55's will be similar to my 2010.

roadPilot

Yup, I'm coming out of a '12 3.5 EcoBoost with a 3.73 and am going in to a '15 5.0 with a 3.55. Lotsa highway miles (work commute - it's my "winter" vehicle) but still haul some ATVs, trailer, lumber, and such.

zx12-iowa

Let us know your thoughts on the difference.

roadPilot

I've put 53K miles on my EB. It's been largely trouble free, but I get the occasional 'studder/shudder' when stepping on @ ~50 mph. Not happy with the mileage (15.9 mpg overall). Towed great (as heavy as a '70 Mustang from WV to MI).

I don't have the '15 yet, but I have put about an hour on a demo. Nearly the same truck (5.0, 3.55, Screw FX4) as what I have on order, but with the 5.5 bed instead of the 6.5 bed. It's solid, no real appreciable different in the city (due to lower torque and taller gear) and it sounds great. Will have to wait to tow to determine how the truck reacts.