A body 8 1/4 rear end swap

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Aside from being about 8" too wide, perches on the top of the tubes, and the later ones being a 5" bolt circle and some having a pinion flange instead of a yoke; I don't see a problem...
 
Professor Fate said:
Aside from being about 8" too wide, perches on the top of the tubes, and the later ones being a 5" bolt circle and some having a pinion flange instead of a yoke; I don't see a problem...
Click to expand...

You can do anything, it’s just about how much work it is…
 
It matters if that truck rear came out of a 2wd or a 4wd. Only the 4wd had the spring perch on top of the tube, 2wds were under /if I remember right. I know Dakota's were.
 
I have a half ton 2WD truck with an 8.25. I can get some pics and measurements tomorrow.
 
My 2wd 3/4 ton has the Dana under the springs...
My 2wd Dak ('88) is over the springs. Yes, the 4wd Daks are under the springs.
 
if you're looking for a bigger rear to swap out an 7.25 or to go to big bolt pattern cheaply, your best bet is an 8.25" out of an XJ jeep cherokee. it's about the right width for a duster (about 60"), and the most common gear ratio is 3.55 (what autos came with). you can occasionally find 3.73's if it had a tow package or 3.07's if it had a manual. the spring perches are also 43.5" apart, although the spring goes over the axle, not under. most come with 9x2.5" brakes
 
That’s what I’m wanting to do. Get rid of the 7.25. I was wondering about a Cherokee 8.25 if it would work. Im also considered an explorer 8.8.
 
I would suggest the F-Body 8.25 as well. Same width as a '65-'67 B-Body.

Still have to move the spring perches, I cut them down the center and break one half off then set the new perch next to it to set the angle before tacking it in place. Then remove the remainder of the old perch and weld the new one up.

Sounds like it is a similar width to the Cherokee one, but probably going to have a taller ratio. I did find one with a 3.21 gear in it, but pretty sure that is the deepest ratio an F-Body came with.

Not saying it is the best swap, just another option.
 
DionR said:
I would suggest the F-Body 8.25 as well. Same width as a '65-'67 B-Body.

Still have to move the spring perches, I cut them down the center and break one half off then set the new perch next to it to set the angle before tacking it in place. Then remove the remainder of the old perch and weld the new one up.

Sounds like it is a similar width to the Cherokee one, but probably going to have a taller ratio. I did find one with a 3.21 gear in it, but pretty sure that is the deepest ratio an F-Body came with.

Not saying it is the best swap, just another option.
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around here FMJ's are long gone in junkyards. can find dozens of XJ rear axles within a 40 mile radius of me for under $150 on facebook marketplace
 
michiganpat said:
around here FMJ's are long gone in junkyards. can find dozens of XJ rear axles within a 40 mile radius of me for under $150 on facebook marketplace
Click to expand...

No argument. Just adding an option. And the Cherokee is a better option if you want a shorter gear, too.

There are 2 FMJ's in the local pick your part yards as of weekend before last. One is an M-Body and has the 7.25" peanut rear end, but the other is a station wagon and should have (had?) an 8.25". Buddy got the spindles off the M-Body. So they are still a possibility around here, even if they are far rarer than they used to be.
 
for what it's worth, just picked up an XJ rear, and drum face to drum face it measures 60.5", about 1-1.5" wider than I had read (and hoped) on the internet....based on my measurements of the current wheel/axle combo to the wheelwell, it is going to require some significant positive offset to run a big tire....
 
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