Rear Diff

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Jun 7, 2026 | 07:58 AM

56fordguy

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Cross-Country

Joined: Sep 2011

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Rear Diff

My 56 f250 has 4.56 rear gears with a y block and 4 speed. I would like to get different gears or different rear end. I get to 55 ish and it's just screaming at 3000 rpm. What are you guys using? I want to keep the 8 hole x 6.5.wheels. thanks

Jun 7, 2026 | 08:26 AM

pintoplumber

Cargo Master

Joined: Feb 2006

Posts: 2,317

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From: Lititz PA

3000 won’t hurt your y block. I often spin mine up to 4500 on a shift. But I can see if you want to drive on a freeway maybe a change is in order.

Jun 7, 2026 | 08:33 AM

56fordguy

Thread Starter

Cross-Country

Joined: Sep 2011

Posts: 91

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Thanks for responding. I would like to go further distances. With things I read to change to 3.73 I need a different carrier and a thicker ring gear. I hear, a rear from a 67-72 f250 will work. Any other thoughts or ideas?

Jun 7, 2026 | 08:44 AM

56panelford

FTE Legend

Joined: Oct 2005

Posts: 283,862

Likes: 8,352

From: northwestern Ontario

maybe this guide could help find you something to look for
https://www.blueovaltrucks.com/tech-...-door-sticker/

Jun 7, 2026 | 08:57 AM

56fordguy

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Cross-Country

Joined: Sep 2011

Posts: 91

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Ok thanks

Jun 7, 2026 | 09:24 AM

55F250

AirForceVet

Joined: Mar 2004

Posts: 612

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From: Spotsylvania,Virginia

Quote:

Originally Posted by 56fordguy

I put a 1968 DANA 60 with 3:73 gears in my 1955 F250, bolted right in with no problems. I'm running around 2000rpm at 45mph with the C6 transmission.

Jun 7, 2026 | 09:34 AM

52 Merc

Hotshot

Joined: Oct 2009

Posts: 16,188

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From: Burbank, WA

3000 isn't screaming. It's where these old engines were designed to run. You're just used to quiet, modern cars with double overdrive that barely idle at 80. Even my 460 lump in my 87 F250 with 3.54 gears runs right there at 70 on the highway. I will agree if your goal is to do 70 on the highway a gear change is in order. And yes, a Dana 60 from an F250 up to '72 is a bolt in and will make your life much easier. There are plenty of them out there. Find one with the gear set you want and go for it.