Gearing Change major difference

[Sidewinded_idi]

im not affiliated with hem but frenchlakeautoparts on eBay supplies me with a 75k mile 4:10 limited slip rearend for cheap. Everyone else was around8-900 I paid 320 shipped complete from drum to drum. I mainly wanted to say that going from 3:55 to the 4:10 really makes this turbo 7.3 shine. It really tows like a dream but as heavy as I haul I’m seriously considering @towcat reccomendation of 4:56 gears. Right now with the 4:10 I’m at 1800 rpms at 60mph

 

[Thewespaul]

It’s a big jump, basically it makes the truck a dedicated tow vehicle in my eyes, just depends on what you want to do with the truck, I like the driveability of 4.10s

 

[Sidewinded_idi]

It’s a big jump, basically it makes the truck a dedicated tow vehicle in my eyes, just depends on what you want to do with the truck, I like the driveability of 4.10s

That’s my issue I mainly use the truck for transporting equipment which I would love the 4:56 but we do use it for family trips as free fuel is hard to beat so that would be the only down time to them. Anyone know what 70mph would be with them and an e4od stock tires?

 

[Thewespaul]

Online calculator says 2700rpms

 

[towcat]

one thing to keep in mind, I have close to a million miles of logbook time on a NA F450 IDI. I've also driven bigger and older and more underpowered than my F450 (1959 Chevy Spartan 90) and I've driven the big horse 18 speed monsters. There is nothing worse than a tow unit that has improperly matched power/trans/rear to the target weight load you're hauling.
The Nostromo(my '92 F350) is clear proof if you are hauling up to a 15k trailer, the truck performs effortlessly and as a result, the driver is not as tore up when he gets to the drop. Stock motor, turned up pump, ATS 093 aftermarket, 4in straight exh, stock clutch and ZF5, 4.10LS rear riding on 215/85/16's is the perfect combo.....for this truck. What do I look for? When I let out the clutch in 1st gear, I like being able to just nudge the throttle gently to prevent load up. From there, I want to roll on the throttle and have the torque take me up to the next gear. Shift at 2200 rpms. Take it up a little higher for 3rd and 4th. usually 2600 rpm for shifting. When I get to 5th I don't mind taking it up to redline as long as the conditions allow. The truck cruises effortlessly on flatlands and up the Grapevine north or southbound. only time I drop gears is when there is traffic.
My F450's are driven the same way other than I am limited to 75mph due to running out of rpms due to gearing. When I hit the hills, I'm dropping gears. no choice, it's the nature of the beast. Ironically, my IH 4700's with the vaunted DT466 is no better. as a result, as long as the combo matches the load weight, you're golden.
nice thing about the F350 is the suspension isn't beating you to death like the bigger boys are guaranteed to do to you.

 

[towcat]

just found a pic of the IH. I drive to the shop with the f350 CC and tow it home. If it is left at the shop, vandals love to pick on it.
even the 4700 is a big *******. 24ft steel deck 102" wide. "if it fits....it ships.....damn the DOT, just run it! "

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[Thewespaul]

Yep our 4700 gets up to 65 real well but that’s all it will do

 

[towcat]

Yep our 4700 gets up to 65 real well but that’s all it will do

i had the ECM reflashed for EMS level performance and the speed limiter was killed at the same time. Don't do it. the fuel bill the following month was ungodly.

 

[Thewespaul]

i had the ECM reflashed for EMS level performance and the speed limiter was killed at the same time. Don't do it. the fuel bill the following month was ungodly.

Well employees are gonna run this truck so the limiter is a good thing in my eyes

 

[u2slow]

I'll vouch for 4.10 with a '94 turbo IDI 5spd 4x4. All I have left is the rear end now, but it worked a boatyard since new. Frame eventually bent from too much tongue weight. Hauled 30+ foot boats when required.