I'm just about to pull the trigger on a 2010 king ranch due to the awsome deals being offered right now.

There's pretty much no question that I'll end up throwing on some 35 inch tires before long. I've done my research with regards to wheel offsets/backspacing, levelling kits etc but my question is this......

Will I notice much of a difference in torque between the 3.73 and 3.55 rear ends?

I'd really like the 3.73 with the bigger tires but there are far fewer trucks (king ranches specifically) to choose from with the 3.73. It would be a lot easier to find a truck optioned out exactly as I want it with the 3.55's.

Anyone have experience driving both? What would you guys suggest?

Any thoughts would be appreciated

 

If you are going to go with 35" tires. you will really need more than a 3.73, no matter what you buy at the start.

 

Since you are buying a heavily equipped F-150, then you probably want the extra 400+ pounds of payload of the max tow package that gets you the 3.73 gear. I agree with Kingfish, I'd want 4.56 for 35" tires. Heck, I wanted it for my old 33's.

 

Yep. ^^

That's one of the heaviest models in the lineup so it's already behind the curve.

BTW - just because you can does not mean you should. It's not a powerhouse to begin with, so soon after the 35's and lift I expect to see you posting back here wondering where yer power, mileage and throttle response went.

Factor in a custom flash programmer along with the other mods (you'll need tire-size adjustment anyways in the PCM to get the shift points and speedo back to their proper states, and of course the gearset data as well) - and certainly the 4.56's or even deeper if you plan on towing anything sizeable.

Did you also consider the impact on yer warranty? and the long-term effect on the tranny?

Good luck - I hope you know what yer in for ...

MGD
_________________

 

Thanks for your concern my good man.....this won't be the first truck I've lifted and I have indeed already factored in the need for a programmer.

Mostly I was wondering if there would even be any noticeable difference between the 3.55 and 3.73 gear set with 35's on the truck?

If not, I will likely save a couple grand on the initial purchase and use it towards the 4.10's or lower.

The heaviest thing I'm ever likely to tow will be a 5-6 thousand pound boat......and even that won't be going very far.

 

Thing is that even with a 3.73 and 35's, you will be working that trannie quite a bit. Possibly even to the point of early failure.

 

I had 33's on my 01 screw 2wd with the stock gears, which i think were the 3.31 for over 5 years with never a problem. I sold it that way too. Now i have a 2010 with 35's and the fx4 with the 3.73. Maybe one day il go bigger, i need to see if that will void the warranty. My lift and tires were put on by my dealer so im good with warranty there.

 

With stock tires there is only about a 200 rpm difference between the two gear sets so with 35's I don't expect you would feel much of anything.

 

If you are going to change gears after the fact, then it doesn't matter what gears you get. If you think you won't change them, then for sure 3.73s without a doubt. Going to that large of tire, you really need some 4.56's to get you where you need to be, or lower.

 

I have been perfectly happy with my set up. 35" Nitto T-Graps (81lbs ea.) with the 3.73 rear. Now I do have a Gryphon...but I know PLENTY of guys with 35's on their 04+ F-150's with stock gears, and I never hear complaints...

 

3.55 on the 09-10 MY trucks are essentially equivalent to the 3.73 on the 04-08 MY trucks, and plenty of them had 35s on stock gears. I'm not an expert on this subject by any means, but I have read a lot about gearing on F150 forums and Jeep forums. From what I've read there is a negligible difference in actuality between 3.55 and 3.73. IMO I wouldn't worry about it and get the truck that had everything I want. The money you save can go towards regearing in the future to something significantly better like 4.56s or something similar.

 

Thanks man......good to hear from someone with actual experience with this set up.

 

I'm starting to lean in this direction. When I test drove an FX4 supercrew with the 6 speed and 3.55's I was impressed with the way the engine was pretty much always in it's power band. After reading a bunch, I kind of expected the truck to feel underpowered but the transmission did a great job of using the available torque.

 

Well what did you expect? They're guys!

Just ask Cegan about guys

Yer typical redneck hillybilly swingin' tool would never admit there was a problem with his truck that he caused. Hence - no 'complaints'.

However - you simply cannot bypass Mother Nature or Pappa Physics - there are significant and real consequences to rolling diameters and circumferential mass increases this large ( it ain't just the unsrprung weight - it's the peripheral rotational mass as well ). Power, braking, suspension control, etc - all suffer for it.

Ergo - they are in denial. A classic guy thing.

The only thing helping is the massive torque, and breadth of same, the 5.4L produces. (The peaky little 4.6L car motor need not apply). If you think you will not get tired of yer tranny constantly shifting - which is what the 6-speed does a lot of already stock - good for you. I know it would drive me crazy. Plenty of complaints on that right in this forum.

Anyway - it's been good jawing at ya - good luck, sir.

OP - Yer gonna love that new truck


MGD

_____________________

 

"Yer typical redneck hillybilly swingin' tool would never admit there was a problem with his truck that he caused. Hence - no 'complaints'."

You assume that is who I am, and/or who my friends are? And only people like that would put 35's on his OR her truck, right..?

You, my friend, are a closed minded idiot...IF and I emphasize..IF...that is your true belief (which it certainly seems like it is).

It sounds like you have NO personal experience with running 35" tires on stock gears...so your input on this subject really isn't worth our time.

Fact of the matter is....it will work....it IS working for COUNTLESS amounts of F-150 owners. These trucks are tough enough to handle it, and if you have Tranny shift issues...get yourself a programmer, or if you really want to...new gears.

Like, I said, I am perfectly happy with my setup, which I have been running for 10,000 miles. Before that I ran 325/60/18 (33.5") with NO tuner for 60,000 miles. And I was perfectly happy with that setup as well.