Gearing: 3.73 to 4.10 or 4.56?

GaryMc

Explorer
My '99 Ford is currently geared with 3.73 gears (Dana 44 front and 60 rear, I believe) and I am running 33" tires. The overdrive shift points are a bit jacked due to the tire size and I am looking at having it re-geared. I'm curious as to whether or not going to 4.10's will make a reasonable difference? I know 4.56's will make it strong off the line but I am very concerned about highway performance, high RPM's and fuel mileage.
Also, as far as I can tell there is no available gear ratio between 4.10 and 4.56 with my differential setup.
Thoughts, experiences?

Thanks for you time and knowledge-

-Gary Mc
 

alexrex20

Explorer
4.56 would be overkill for 33s, especially if you're trying to preserve highway performance. 4.10 would be the sweet spot, and be sure to throw in a pair of lockers while you're in there. ;) :D
 

Stumpalump

Expedition Leader
What engine do you have and how much weight? I have never heard anybody say they wish they had put in higher gears than they have but have heard a hundred times they wish they would have gone lower. 4.56 would be nice but 4:88 will pull a 35 when you make the swich to them someday or handle a heavy load real nice now if you don't have a v10 or diesel.
 

GaryMc

Explorer
How did I forget to forget to include the engine specs?!? It's a 5.4 liter Triton V8. The van is being built as a lighter version of a Sportsmobile. The only thing I ever tow is my raft and with it fully loaded and on the trailer it's about 3500lbs total.
As far as 35's go.... No way in Hell will I ever go to a tire that big. I just don't need or want that. 33's suit my purposes just fine.

Thanks-

Gary Mc

What engine do you have and how much weight? I have never heard anybody say they wish they had put in higher gears than they have but have heard a hundred times they wish they would have gone lower. 4.56 would be nice but 4:88 will pull a 35 when you make the swich to them someday or handle a heavy load real nice now if you don't have a v10 or diesel.
 

cwsqbm

Explorer
For a modern gas motor with an overdrive automatic transmission, I'd go for the 4.56 with 33's. My last truck came from the factory with 4.10 and 31's and was about ideal, and it didn't run at high rpm, even at 80mph. If you think the 3.73 isn't right, the 4.10 probably isn't a big enough step. Mileage difference between 4.10 and 4.56 would be minimal, and may not worse than the 3.73 as the transmission will be able to go into overdrive at lower speeds, and be more able to stay in OD while going up minor hills.
 

Loopie

Adventurer
A lower gear ratio can save fuel at every point on the map up to, but not past, the appropriate engine RPM in the highest tranny gear.

And yes..the "Cammer" motor, the Triton 4.6/5.4 are not the same as the older V8's...they need to rev a bit more before they wake up or even run "efficiently"
 

Brit55

Observer
Gary:

I just regeared my 07 E350 and may be able to offer some info for you. I went from 3.73 R&P with stock 29" tires to 4.30 R&P with 33" BFG All Terrains.

After the installation I'm seeing exactly the same engine RPM at 70MPH as I did with the original gearing and tires. I measured the speed using a GPS to avoid any speedo errors.

Like you I am not planning on loading the van too heavily or doing any significant amount of towing.

Hope this helps,
Andy
 

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