No, not how I use my truck. It's normally pulling a trailer and used on weekends and vacations only. If used as a daily driver with lots of highway miles it might not be for everyone. There's a stretch of I-10 with a posted speed limit of 80...I'm turning 3,000 RPM's at that speed, not so good if you're concerned about fuel mileage. I think a final gear ratio of 4.30 is ideal for towing and highway travel, the 35's should give me that final ratio. If I decide to stay with the same tire height...no regrets at all. Hope this helps!

 

Well after sitting on the fence for a couple of years, I had to finally pull the trigger on regearing. I went up a size in tire to a 33" and I am pulling more weight now with the recent purchase of a RZR XP 4 that sits in my 7500# bumper pull toyhauler. The truck was really struggling on some of the grades out here in the west. On mountain pass outside Las Vegas I could only pull 2nd barely! At one point after goint to 1st I thought we were going to slow down to a stop, but it didn't.
I have a 2000 F250 V10 supercab 4x4 Auto with 140K on the clock. It currently has 3.73s and as I type this, I am waiting on the 4.56s to be installed. I can't Wait! The wife and I debated on putting this much $ into a gasser with 140K but in the end we decided to keep the V10 going because I truly love this truck.
I will post up results after the break in.
I was going to go with 4.88s but made the last second decision to 4.56s because although it is not a daily driver, around here 80 is cruising and wanted to be able to keep up!

 

Give us an update as soon as you can!

 

Don't fear the gear!

The previous owner of our '99 F350 V10 4x4 dually had 4.56s installed, and they're about perfect for towing. We pull horse trailers mostly, so we don't go past 65 regardless, and we're taching about 2200RPM at that speed. So far empty the truck gets about 14mpg, and towing we're at 11-12.

No, we don't hot rod the truck.

Next stop, 5 Star tune and y-pipe, catback exhaust and a better intake. And open up the rear diff and see if the PO had the sense to install a limited slip in the rear, the tag says it was originally a 3.73 open axle, and I really want to have as many wheels turning at the same time as I can get next time I have to tug a big loaded trailer through the monsoon mud out here.

 

I keep reading posts about gears and well I'm debating between 4.30 , 4.56 and 4.88. I have my f250 with an 8" lift on 37s. With stock 3.73 it's good on freeway but feels like I'm towing when city driving and stop and go traffic

 

im planning 4 88's for my 09 on 37's.

 

First of all thanx to all this is an old thread but a good thread for all ford v10 superduty owners looking for information on gearing and its effects on driving....i too am leaning towards this gear ratio 4:56 for an upgrade seems like a good choice for guys who want to run 33''-37'' tires for tow or play...you can go up or down a size from 35'' tires to set your rig up for towing or mudding.... and Yukon seems to be the popular choice of gears.

 

When my truck was ordered the only boxes they checked were for V10, 4x4 and 4.30 LS axle group. It's a stripper model that came with an am/fm radio and two speakers and when I weight it the truck came in around 5600 lbs with a 1/2 tank of fuel. It currently has 168k on the clock and I put a set of 33's and it still pulls my friend's heavy trailer and my portly jeep just fine. If I was going to set up to 35's or 37's I'd defiantly get some 4.56's or 4.88's

 

Resurrecting an old thread, but a good one. Based on my truck's usage and possible desire to go to a larger 35" tire (currently 33") going with 4.56's in my '03. Have appointment next Wed. 11/2. I'll report back from time to time with any updates. Thanks FTE!

 

Please do. Eventually I'm going to put 4.56s in mine

 

Love this forum, it help keeps my 03 F250 V10 running.
I have the rear gears and bearing pack to change gears to 4.56 and just gotta get courage to do the upgrade myself. I’ve done most of the work on my vehicles but never a gear change. I’ve found a really good write up that I’ll follow.
it’s great to hear all of these results. Any one know a good source for all of the changes to the Dana60 in the front?

 

Look forward to towing after 500 mile break-in. I'm not abusing it during break-in, but, for example, that 2nd gear shift and delivery of torque and power as you go through 2nd gear, it's like an "8.6L" now.

I captured a few numbers just for curiosity. Appreciate the smoothness of this motor especially at the higher RPM's. A quick scan of mpg shows nothing worth reporting yet (no major changes one way or the other). I'm anticipating mileage to improve / degrade in different use cases. Motor is definitely running "freer". I'm not an over 68mph driver (towing/not towing) which helps. A little louder in the cab, but I like it, especially after putting that MagnaFlow on.

Here's my numbers:
'03 V10 Engine stock w/MagnaFlow muffler
285/75-16 (2 sizes larger than stock) / GPS shows speedometer is dead-on

Before/After (3.73 / 4.56) +/- 50rpm, torque converter "locked-up"

50mph
1400 / 1750
OD off - 2000 / 2450

60mph
1700 / 2100

65mph
? / 2250

70mph
2000 / 2450

 

Those numbers look about perfect to me. Now I just need some more money. I took a pay cut to leave a job that was killing me and now I'm having to learn how to be poor. I wish I'd planned ahead and done my gears before leaving. Eventually though 4.56s WILL find their way into my truck.

 

I need to do this too, as I run 35" tires. Is Randy's Ring & Pinion found at https://www.randysworldwide.com/

Thanks

 

Just short runs this year to our local lake, but got some elevation changes in this past week (and in 100 degree plus heat). Folsom CA to Bullard's Bar Reservoir. Towing 6K lbs boat/trailer with my stock '03 V10 w/4.56 gears(installed late last year) was much more efficient / effortless compared to the 3.73's that were in there.

Some highlights:
- From a standing stop it really gets up to speed quickly / barely any throttle to get going
- Cruising at 65-68mph / ~2250-2350rpm. Smooth and very easy to accelerate / pass without downshifting.
- Winding/Elevation/Slow/Twisty Sections - Feels like I'm in the right gear more. Less downshifting.
- When I would go down to 3rd or 2nd and tach ~3500 rpm it pulled with authority.
- Downhills / engine braking better too.
- Mileage - Don't usually track this too closely, but got 7.6mpg towing roundtrip (hand calc.). Unloaded it's been getting 10 city / 11-12 highway.

Overall, happy with how it's working and looking more forward to renting that 8-10K lbs travel trailer down the road.