1ton and 3/4ton 14blt difference

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squarebfan

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I purchased a 1 ton 14blt ff to go under my 3/4 ton frame.

What all do I need to do in order for it to work? I know the spring perches need moved but is that it?

Thanks in advanced
 

Bextreme04

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There is no difference as long as they came off a square. There is a difference if it came off a C&C frame. Do you not have the original axle from your truck? If you scrape the gunk off the top of the passenger side axle tube, you can read the axle code to know what it originally came off of and what gear it is. Pics?
 

squarebfan

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I do have the original one that came out of mine which was a semi floater.

The other difference that I see are the spring perches were narrower and the axle tube are diff length on the 1ton.

Driverside is shorter then pass side
 

squarebfan

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Will it still work under my pickup? If I just move the perches!
 

Bextreme04

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oops, looks like I was wrong. 3/4 ton has a different perch width than 1-ton, which is different than C&C. Here's a thread discussing that and the correct perch width for each. https://www.gmsquarebody.com/threads/3-4-ton-vs-1ton.5964/page-2

You will also have different shock mounting location. If you absolutely MUST use that axle, you will need to cut the perches and shock mounts off and move them to the correct positions(or most likely just get new perches to weld on). Or just go get a 3/4 ton 14BFF... they are actually more prevalent than the 1-ton setup since most of those will be a dually Dana 70
 

squarebfan

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Yeah, ok I'll check it out! Thank you

That's fine if that's all I gotta do, I already have new perches and shock mounts. Just wanting to double/ triple check myself with other people before go any further.
 

eskimomann209

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Shooot, if you can weld and plan on putting that kind work into it you coulda got axles from a newer truck already disk converted.
Most people that stress on the “will it fit” can’t or don’t want to weld.
I, myself, would slap on some matched one ton axles from a newer truck in a heart beat.
But then again I dunno if you have a C or a K chassis.
 

squarebfan

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I got a k chassis, doing a d-max swap, I bought the axle that came out of a crew cab. Moving those and re-welding don't seem that hard to me.
 

eskimomann209

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Interesting, couple people doing that right now. Be sure to add some build pictures. Lotta interested folk I’m sure.
What d max did you choose?
Going with the Allison trans?
 

squarebfan

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I have the lbz, and Allison w/ t-case, so I have to install a ford d60 in the front
 

Bextreme04

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I was gonna say, If you are doing all that you might as well have just gotten a whole set of axles from a ford superduty. You probably should have gotten the AAM axle from the Duramax donor truck too. It would have been an 11.5 AAM full-floater with disk brakes.

Are you getting an earlier Ford D60 that is set up for leaf springs or a later one with a 4-link setup?
 

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There were different sizes in brake shoes depending on the GVWR.
 

squarebfan

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I have a earlier year for leaf springs! This is the 14blt I have
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Bextreme04

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I have a earlier year for leaf springs! This is the 14blt I have
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Nice... that's a second design axle so it's 89-later. I have an earlier one without the finned case. You have the biggest version with the 13x2.5" brake drums, but oddly enough you don't have the slide-off drums that should have come on a second design 1-ton SRW axle. Those things are stupid heavy, I just rebuilt my whole axle with new bearings, brakes, and added a Yukon Grizzly locker to my open 4.10 carrier. If you end up doing something similar, I highly recommend you spring for the crush sleeve eliminator kit, because the 14BFF crush sleeve needs about 600lbft of torque to START crushing... and it sucks.
 

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