8 3/4 Rear end questions

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64physhy

64physhy

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Can the center sections be swapped with another center section type? I have a 741 with 3.23 gears, not sure grip. I want to swap for a 742 or 489 for the larger pinion stem so I can eventually go with more power (have my eye on a good 360 for sale locally). The rear end is not yet installed in the car, so I'll need to get a driveshaft. Are the lengths of the pinions different, too? This is going in a '64 Barracuda.
 
all 8 3/4 chunks fit all housings with out any changes as far as i know i have 4 different chunk an they all interchange with out a drive line channgeif the u jonits are the same
 
Should interchange BUT be sure when ordering a rebuild bearing kit to specify which case your doing. That part is different from one to the next. Different pinion sizes.
 
The rear end I have has the SBP. I was going to use it in my Barracuda, but now plan on using it in my '74 Duster. So, I need to get axles with LBP. I also plan on getting a sure grip, or some kind of limited slip. I was looking at axles, and at some places, it has different axles for different sure grip types. What's the difference? I though you could pull an open section out and put a sure grip in with no other changes.
 
I just replaced the 7 1/4 with an 8 3/4 in my 66 Dart 6 cyl. 904 auto.I used a d.shaft from a 73 swinger 318 904.My center section is the .489 with big yoke.Iused a cross-over 7290 u-joint.(I didn,t have to cut the shaft,it fit perfect)also have moser bbp that I bought through a guy on this site.15%cheaper,with green bearings.So now I can swap centers without having bearing issues.Hope this helps a bit?Also bought a auburn suregrip(new)
 
pettybludart said:
I just replaced the 7 1/4 with an 8 3/4 in my 66 Dart 6 cyl. 904 auto.I used a d.shaft from a 73 swinger 318 904.My center section is the .489 with big yoke.Iused a cross-over 7290 u-joint.(I didn,t have to cut the shaft,it fit perfect)also have moser bbp that I bought through a guy on this site.15%cheaper,with green bearings.So now I can swap centers without having bearing issues.Hope this helps a bit?Also bought a auburn suregrip(new)
Click to expand...

Thanks for the info. Who on here sells the BBP axles?
 
Make sure that if the third member you're swapping in needs thrust spacers that you have them in there before you put the axles back in place.
 
The 741, 742, and 489 are the same, but not all 8-3/4 centers are the same. The earlier, I think '63 and earlier, sure grip centers were different. Something about the thrust block or button that I don't understand. There's also something I don't understand about some of the A-body BBP axles and the thrust button, and the axles being too short sometimes, or the button needs to be removed. I don't know. This all has to do with the axles, and not the driveshaft length. There are the conversion u-joints, as mentioned earlier, so if in a bind, you can use one of those. You can also swap the yoke on the 741 and 742 cases from small to large u-joint, but not on the 489.

Read this: Guide to the Chrysler 8-3/4"
 
Thanks guys. I'll be dropping you an email when I get back to the US, Trevor. I'm also looking at buying a suregrip 742 with 4.10 gears from another member. I wanted to make sure everything would work together. So, I have a SBP 8 3/4, plan on getting a sure grip 742 pig and convert to LBP with green bearings. Anything else I should know?
 
hey guys,

I'm not trying to butt into the discussion but you all seem to know what you are talking about when it comes to a 8 3/4" rear end. to make this as short as possible, I'm getting my '65 dart gt next weekend from California. it has a 7 1/4 rear end in it. my Dad told that i need to up grade to a 8 3/4 cause I'm going to bigger motor.

I'm having a hard time finding one for an A body locally. do you know if any one who has one, what do they run as far as price, etc. also I'm finding a lot for the C body. i know you can cut it down to fit an A body, how difficult is that, and what are you thoughts?

thanks,
matt
 
matarcher said:
hey guys,

I'm not trying to butt into the discussion but you all seem to know what you are talking about when it comes to a 8 3/4" rear end. to make this as short as possible, I'm getting my '65 dart gt next weekend from California. it has a 7 1/4 rear end in it. my Dad told that i need to up grade to a 8 3/4 cause I'm going to bigger motor.

I'm having a hard time finding one for an A body locally. do you know if any one who has one, what do they run as far as price, etc. also I'm finding a lot for the C body. i know you can cut it down to fit an A body, how difficult is that, and what are you thoughts?

thanks,
matt
Click to expand...

A B body is almost a bolt in. It's about 3 1/2" wider overall than an A body rear, but you can get wheels with more backspacing to ofset that. The spring perches are 1" wider on the B-body rear end. They will fit like that, and there are a lot of people who run it that way, or you can move each perch in 1/2".
 
Find a B, C or truck rear axle and have it shortened. Probably less expensive than an A body 8.75
 
these rear ends are getting hard to find i picked one up 2 weeks ago 489 center drum to drum 200 dollars 10 miles from my house
 
Well you got a score there,I paid $200 just for a housing and some backing plates.Yes,they are getting hard to find and after the work and purchasing I could have bought a brand new Dana S60 from Moser for $1700.Which I,m sure I,ll end up doing in the future,for one of my cars?
 
i did that also bought strange dana just don't say i should get this and this next thing you know 2500.00 bucks to your door step then you look at ad say i thought this was 1700 dollars bought 83/4 price was to good to turn down
 
I got mine free about 8 years ago. It's an SBP with 2.76 (or is it 2.73?) open. I was going to put it in my barracuda, but time and money have prevented it. Now I want to put it in the Duster .I think now I can squeeze it in, but needing to get new axles and a 742 or 489 sure-grip with a 3.91 ratio seems like it might end up costing as much as if I just found a complete drum to drum rearend that already has what I want would be close to the same price. 742 and 489 sure grip centers seem to be running around $500-$600 for good used ones, $255 for the axles. New drums. Will I need to replace everything for the brakes or just the drums? If it's everything, then there's even more cost.
 
I found a 8 3/4 out of a 383 68 Polara for $60.00. Will that work? What does it cost to be shortened, and who does that??
 
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