4.10's VS. 3.54's

[UndrGrndPrdcts]

My dad's truck currently has 3.54 gears. He runs 33 inch tires. The stock 3.54 rear axle is an open differential. He has a good limited slip rear with 4.10 gears and a matching front end. Swap is not a problem we have done them before. Would he be better off to keep the 3.54s or would putting 4.10s in be OK? He doesnt drive far and the truck is non turboed right now. Or would 4.10s really kill his mileage and cruising speed?

 

[Brianedwardss]

Does it have overdrive?

No overdrive: 3.54
Ya overdrive: either, depending on what the truck is used for.

 

[93_444idi]

i ran 33s with 4.10ls non turbod and it was fine. also ran 36s, which turned it into a dog. obviously you're gonna lose top-end but you'll be a lot better off with 33s with 4.10 gears than 3.54. big difference out of the hole

 

[UndrGrndPrdcts]

It's a 91 with a 7.3 and a 5 speed so assume the 5 speed has an overdrive like most do. He doesn't really need top end and would probably be better to have the lower end power. I just wanted to make sure it wouldn't completely kill the highway cruising.

 

[Silver Burner]

It'll bring his RPM's from 1600 or so at 55 to 2000 or so at 55. 5th gear is overdrive at 0.76 to 1

 

[bike-maker]

I've got 33's and 4.10 gears. It will cruise down the interstate at a comfortable 70-75mph. Right about 60mph (about 2000rpm) seems to be the sweet spot; on longer trips at 60mph cruising speed, I still get right about 18 mpg. Running it up to 75 kills the mpg, but I'm not sure by how much. It's geared a little steep for the interstate unloaded, but it's just about perfect for towing my 5er around. Unloaded I shift into 5th gear at about 35-40mph, with the 5er hooked up, I shift into 5th at about 55-60mph. It takes some RPM and throttle to keep that much weight moving.

 

[pedro_8149]

my truck has 3.54s and i am running 33" tires, and its non turboed, and has the e40d trans its a **** in the bottom end, and i do a lot of highway driving and some firewood getting, would 4.10s be a good swap or just leave the 3.54s

 

[Optikalillushun]

mine with 3:55s, N/A, 5 speed and 35s runs along just fine...only issue is pulling long hills i cant use od...but in 4th i can pull said hill pretty easily.

 

[Ranger5.0L]

Just did a dana60 swap on my f250. Stock it had 410's and sucked goin any faster than 60 the new axle is 354's swapped the rear gears to match and couldn't be happier with it. What little I might have lost in pullin power I can deal with. Also running 33's

 

[Diesel_brad]

If you tow and dont do too much highway travel, Hell even towing on the highway go 4:10

If you dont tow and do a fair amount of highway travel, 3:55

 

[gaazuremach1]

I have 4.10 in my dually and I drive it daily 96 miles round trip to and from work. I am avg 15 mpg so I have been considering swapping gears. The only issue I have is that I tow my 10200 lb 38' Forest River with it about 3 times a year as well as my 24' enclosed trailer with my Mustang in it to the track probably 12 times a year. So I was considering changing to 3.73. Both of my Powerstrokes had this setup and was a good compromise. How do you think it would do with these?

 

[bigblue85]

i got 4:10's with a 4 speed and i love them. the power off the clutch is amazing and diesels tend to run most efficient being reved higher. but at seventy im running about 2300 which it loves it and gets around 17mpg with a 6.9 but i had 373 and my 4 speed hated it seemed to kinda hope takin off in first. if its a extended cab or 4 door i would advise the 410 they would be easier on your clutch

 

[fields_mj]

It's a personal preference thing really. My truck is NA and has a ZF5. It had 4.10 when I got it. I drove it from Jacksonville FL where I bought it to Atlanta that night, and then to Indy the next day. The truck would do 80, even in the mountains, but it was starting to shake at that speed. 1800 to 2000 rpm is about the sweet spot for these trucks, and with 4.10 gears, that was at about 55 mph. I changed to 3.55 gears, and now I'm running 67 at 2000 rpm. This took me from 16 mpg to 18 mpg (I need to have the fuel system gone through) and running at a lower RPM also quieted things down a lot in the cab. The truck still starts to shake at about 80, but driving 60~75 mph she drives nice and smooth. I mainly drive up and down the road to and from work, and occationally haul firewood or a trailer so 3.55 gears made the best sense to me. I'm running stock tires (just under 33"). The next set will be slightly taller. I would be completely comfortable hooking onto 10K and hauling it across the country, but I also realize that I might not spend much time in 5th gear with it. Now, if I routinely hauled over 4K with the truck, I'd probably opt for the 4.10 gears, or better yet with 3.73 gears. I wouldn't put 4.10 gears in anything that I wasn't going to tow/haul/pull with a lot.

Well, that's my 2 bits anyway.
Mark

 

[SparkandFire]

My last truck (the '87) had 3.55's and it was a dog with the C6... But that was really a nice improvement on the freeway over the '86 with a C6 and 4.10's.

Hell, the '86 sounded like the engine was going to self-destruct at any moment (and give those cummins guys something to laugh at as they passed me stranded on the side of the freeway)

It all depends on what your doing with the truck.. Like any other gearing issue on any vehicle. My first car was a '81 El Camino with 2.77 gears and that thing was a royal fat pig taking off from a stop. I used to get passed by grandmas in toyota celicas taking off from a stop light, no joke!

My truck now has 4.10's with a ZF5, and I wouldn't trade that for anything (since I am towing a trailer regularly) Sure, the 3.55's would improve my mpgs a bit, but the numerically-higher ratio really makes a difference with a trailer on the back, and when the hills get steep!

 

[jam0o0]

i've got 4.10's and factory 31.5" tires with a zf5. i really don't like driving it fast. i also skip first when it's unloaded.

if the truck is used for towing get the 4.10's. if it isn't used for long highway drives get the 4.10's. if it's always empty and you drive long distances at 70+mph then keep the 3.55's.