C body 8 3/4 in the doba?

Mopar&vettedude

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I happen to find an 8 3/4 on craigslist the other night. Its out of a 65 fury III, and thought to myself this would be great to drop in. Then it dawned on me its a c body car. Is it possible to drop a 8 3/4 C body rear in our cars or would i be looking to have it shortened to work?
 

4speedjim

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You'd need to shorten it. How complete is it? They're spendy if not complete. Instead of shortening it, possibly use a modern wheel that has the offset way out near the body line. Is that Positive offset? Like your 300. Lots of axle width info online. Try Googling it. IIRC its about 4" wider than what you want. Make sure that its 5 on 4.5 axles. It should be. What you want is a '66-'67 Satellite 8 3/4. You have 59.5" wms to wms (wheel mount surface). 8.25's are a good alternative also, if your not building a 600 hp sticky tire car. Disc or drum brake, handles good hp, light, cheap, used in Jeeps. Ford Exploder 8.8 axles are also an easy cheap hd swap. Exploders have 31 spline axles and Posi's are plentiful. Complete w/calipers and Posi are $200, everywhere. 3.20-3.73s are common, 3.08-4.10 where used.
 

Aspen500

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Like 4speed said, too wide. It's about 5" or so wider than a stock f-body. I've got a '71 b-body 8.75 in mine and it's borderline too long, being about 3" wider than stock. I have 15x8 wheels in the rear with a custom backspacing so they're basically a 15x7 with the extra inch towards the inside. The tires would JUST clear the fender lip, if the suspension could ever go that low. Only thing i had to do was move the spring perches to line up with the springs. All my measurements are approximate only.
 

Mopar&vettedude

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It's full rearend drum to drum. The doba does have 8 1/4 in it now, I was also considering doing the sure grip conversion on that since I'm not trying to make a high horsepower tire shredder. The guy wants 800 for it. It's probably one of the cheapest suregrips I've seen so far.
 

4speedjim

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Since you dont need an 800HP axle, that doesn't fit, Id invest in your 8 1/4. IMO $800 is way high for any 8 3/4 over 60". With the money to buy it, have it shortened, upgraded and brackets installed, you could have a new 60" disc brake Strange D60 built.
 

BudW

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’65-68 C-Body 8¾” differential specs are:
56.750” housing flange to housing flange
46.00” perch center to perch center
61.75” drum to drum

FMJ differential specs are (midyear '80 to '89 FMJ):
54.340” housing flange to housing flange
44.46” perch center to perch center (for all year FMJ's)
59.5” drum to drum (wheel mounting surface to wheel mounting surface)

The width difference between the two differentials are 2.25” (total) / 1.125” (per side).
If a person was to purchase wheels with more than normal offset, the width of the C-body differential might not matter.
I would pay a bit more to get the housing cut down with new ends welded on. Then find a pair of axles for appropriate year B-body width (or get a new/stronger pair of axles made) - but that is just me.

The perches, on the other hand, will need to be cut off and re-welded on- but that is not a biggie.
BudW.
 

Duke5A

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Keep the 8.25" you have and just drive it to an axle shop and have them install a limited slip unit. I would call Doctor Diff and get the unit from him and if you want rear disc brakes he can get you a set of those as well. If you're looking to replace the axle then get something newer with disc brakes already on it like a Ford 8.8 and have it reworked to fit.
 

LSM360

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I agree keep the 8.25. It's strong and you can beef it up as written. And remember how much weight you would be adding with the 8.75.
 

Mopar&vettedude

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I ended up taking the rear end to a shop and found out i had a 7.25 ring gear. So i ended up finding a 8.8 out of a 96 gt had some leaf spring perches welded on and dropped it in. I got 3.27 gears, lsd and rear disc for a little over 700 bucks.
 

Duke5A

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I ended up taking the rear end to a shop and found out i had a 7.25 ring gear. So i ended up finding a 8.8 out of a 96 gt had some leaf spring perches welded on and dropped it in. I got 3.27 gears, lsd and rear disc for a little over 700 bucks.

That is the way to do it right there. Mopar axles are too hard to come by anymore and pricey to build for what you get.

Edit: Just realized I fell for a necro thread. BRAAAAAAINS!
 
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