Rear end gearing Ford 7.3L

[pilotpip]

I'm going to switch from my rockwood mini lite bunkhouse and F-150 to a Momentum 29G and a new F-350. Torn on rear end gearing. My father in law is currently towing a rockwood ultra lite with a 2020 250 that has 3.55gears. He's happy with the combo.

I'm going to be towing several thousand pounds more than he does. I'm trying to decide between the 3.55 and 4.30. In the old days, I would have said 4.30 without hesitation. With the newer 10 speed... not so sure. I went from a 13 F-150 with 3.31 and a 6 speed to an 18 with 3.55 and 10 speed. The difference is amazing. Tons of low end grunt.

For a number of reasons, I'm going to go with a 7.3L. As much as I'd like a diesel, I have no desire to deal with emissions issues, DEF, the CP4 fuel pump, or the $8000 price increase. What I'd like to hear is real world experience with the Godzilla. What are you towing and what sort of performance have you seen? The thread on here with the solitude owner has been good but I'd like to hear from the rest of you.

[SDblueline]

I’m towing 2014 Reflection 293 RES with the 7.3/3.55 gears. Dry weight is listed at about 9100 pounds. I would estimate with full water, generator, food, etc that I’m closer to 10500. I’ve towed 6 trips in the past four months from Sacramento to the Northern California coast, down to Paso Robles, and up into El Dorado County (4100ft elevation). Climbing 6-7% hills at 60-65mph expect 3500-4000rpm in 4th,5th or 6th gear. The engine never seems to struggle, that’s just where it makes it best power. But even in that range it’s quiet enough to talk at a normal level without being drown out. On longer freeway stretches it’ll often get into 9th gear at about 1600 rpm. The only place where I’d like lower gears would be on the north coast country roads where you get very slow, very steep, up-hill switch backs. Not that it struggles, it just take a bit of time to get back up to speed. Overall I’m very impressed. Sure the diesel would have been nice, but the lower upfront costs, simplicity, and sufficient towing capability of the 7.3 was exactly what I wanted.

[rmcrowe]

I am towing an imagine 2500rl with the 4.3 rear end. Its way more than needed for the trailer but standard on the 7.3 tremor. We have about 18k miles on the truck now with 10k towing the trailer. Its been flawless for us.

[pilotpip]

Went with a 350 lariat. 3.55 gears aren't offered so I went with 3.73. I'll have enough payload that I won't have to worry if I decide to go with a 5th wheel instead.

[Grandesigner]

With 3 overdrive gears on the 10 speed, I would go with the 4.30 and will actually do so when I order a new one.

[Grandesigner]

Just ordered an F350 SCSB 4x4 7.3 with 4.30 gears...now waiting 4-6 months

[Pacific Fisher]

I went with the 4:30 on my 2021 F350 7.3 and have been very happy pulling a 310

[powerscol]

Given the 7.3 power curves go with the 4:30. I almost went with the 7.3 but decided to stay with the 6.7, but even then I got the 3.55 gearing as that set up seems to be getting the best fuel mileage for some reason.

[Castlerock]

I went with the 3.73 rear end on my '22 F-350 CCSB with the 7.3. Still waiting for it, but last year I pulled my 260RD with a F-150 with the 3.55 rear end and didn't have any issues. Pretty sure that the 7.3/3.73 combo is going to work out great.

[Grandesigner]

The main reason I ordered the 4.30 was I live at 5k ft and tow up to 10k ft and I'm used to having a turbo make up the difference. I suppose a 4.10 would be fine, but not offered. It might become a 4.10 after I install larger tires when the originals wear out...
Like I said before, 3 OD gears will tame the 4.30 enough. Gotta love the 10 speed.