How do I find an 8 3/4 rear in the jy

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Let’s clear up some misinformation here….

The last year for an 8 3/4” in an A body was 1972

1973 and later cars could have a 7 1/4” with small bolt or large bolt, small bolt for drum brakes up front, large bolt for disc brakes. High performance A bodies in 1973 and later came with disc brakes and the 8 1/4”

The easiest way to check to see if an A body has an 8 3/4” without being able to look under it would be to inspect the brake backing plates. It would have small bolt pattern lugs and 5 studs and nuts to hold on the backing plates, 7 1/4” only had 4. Of course, anything could be changed up over the years, but this is how they came from the factory.
 
Just got back from the yard I only found 73 d 100 with 8 3/4 . Thanks for the replies!

That's not necessarily a bad purchase, depending on how much the junk yard is asking for it and how complete it is.

A-body housings are expensive. If the price from the yard is decent, you can have that '73 D100 housing shortened to A-body specs and the perches moved. Depending on where you're at and who you know this may even be cheaper than buying an A-body 8 3/4 housing. If it's a 5x4.5" bolt pattern axle you can just have the stock axles shortened, and all of the brake parts can be used too.
 
You need to go back and check the center section. It might have a 3.55 in it or if your really lucky it might have a suregrip in it.
Shhh, you’re giving away my secret of finding Suregrip 8 3/4” 3:55’s and 4:10’s in old 4WD Dodge trucks from the mid 70’s. Next thing you know you’ll be telling them to check the C bodies too, especially the 68-70’s, for those 742 case Suregrip’s with 2:94’s that go for cheap.
 
You need to go back and check the center section. It might have a 3.55 in it or if your really lucky it might have a suregrip in it.
And a /6 truck would have 3.91 gears. Last year I got a 489 case with 3.91 S/G from a 73 D100 /6.
 
1971 Dart /6, 3 on the tree, manual disc with 8.75
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There's always F/M/J body 8 1/4 axles.

Every 5th Ave I've seen has one.

...but they are usually a 2.45 gear.
 
Shhh, you’re giving away my secret of finding Suregrip 8 3/4” 3:55’s and 4:10’s in old 4WD Dodge trucks from the mid 70’s. Next thing you know you’ll be telling them to check the C bodies too, especially the 68-70’s, for those 742 case Suregrip’s with 2:94’s that go for cheap.
And we usually paid $50 bucks for them. LOL!

Back in the day a friend of mine mentioned a truck in the junkyard having a 8-3/4 but it wasn’t a suregrip so he passed on it. I checked it out and it was a 3.55 and the best thing was that the bed was missing so I didn’t need to crawl under it to remove it.
 
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A friend checked under his neighbors old Dodge pick up box trailer. It had a 3.55 Sure Grip. He exchanged that out for a peg leg 2.76 for free. Don't overlook that stuff.
 
I've seen a lot of 72 A's with the 8.75. I think Mopar was clearing them out beings 73 was going to the 8.25. A friend has a 72 Duster with /6, A/C power disc and a 8.75.
I've found a lot of trucks with S/G chunks.
 
Find someone to shorten a rear. Then any 8 3/4 housing can be made to work since A body's use the shortest rear housing. Did it all the time.
 
Find someone to shorten a rear. Then any 8 3/4 housing can be made to work since A body's use the shortest rear housing. Did it all the time.
Yup. My Dart has mini-tubs and inboard springs. I'm going to fit big tires and rims into the tubs and then shorten a C body 8.75 to fit. Don't want to ruin my A body one.
You might go back and see about snagging that truck unit. Always could sell it if you don't use it. People are wanting them too. The 72-74 unit will bolt right into a 75-93 truck.
 
Do truck axles have holes and/or a pad to mount a pinion snubber?

I've pulled quite a few 3.55 chunks from A-100 vans and trucks.
 
Truck perches are on the top of the housing because the rear end hangs from the leafs, it doesn’t sit on them like cars do. That would be the only difference besides the location of the splitter block for the brake lines. I have a truck housing here that’s going into my plow truck this spring, I can use that for reference should anybody need it.
 
Look at the end of the axle hub n the center of the wheel. If it’s flush it’s either a 7.25 or 8.25. If it’s dished in it’s an 8.75. You don’t even have to lay down. Pop of the in cap and there it is.


This is what you are looking for.

View attachment 1716031514
Here is what I have.
1st 7.25
2nd 8.25
3rd 8.75

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