Just so I'm 100% clear on an 8 3/4 swap!!!

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Sdriche

Sdriche

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I'm buying a 65 Dart to swap out the rear in my 68 Dart convertible (mine has a 7 1/4 and this is an 8 3/4). I've seen some references that mention 66-76 swaps easily. Others say 65 and up. Attaching pics in the hopes someone can confirm this will work (before I drive 4 hours and buy a whole car). Thanks in advance

rear1.jpeg


rear2.jpeg
 
Sdriche said:
I'm buying a 65 Dart to swap out the rear in my 68 Dart convertible (mine has a 7 1/4 and this is an 8 3/4). I've seen some references that mention 66-76 swaps easily. Others say 65 and up. Attaching pics in the hopes someone can confirm this will work (before I drive 4 hours and buy a whole car). Thanks in advance

View attachment 1715824258

View attachment 1715824259
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Yep, that's a 8 3/4
 
My understanding is that they became available in late '65, but didn't show up on the option sheets until '66.
That's an 8.75 in the pic. Can't promise it's original to the car after 55 years, though.
 
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Sdriche said:
And no issues swapping to a 68?
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No issues other than the normal 7.25 to 8.75 quirks: U joint size may differ, use the shock plates and U bolts from the 8.75, and driveshaft needs to be ~1.5" shorter. Knowing that, it bolts right in.
 
You never know what has been swapped in and possibly be a non factory made up unit, so also keep in mind that the pre-1964 8 3/4 rears were of tapered design which held the brake assemblies in place by the use of a key and locknut. This is not to say that other older rear end designs or from non a body vehicles vehicle can not be used, but just be aware of the differences so you can make informed decisions. A couple of links with good information.

https://www.hemmings.com/stories/article/mopar-8-3-4-inch-rear-ends/amp

http://board.moparts.org/ubbthreads/upload2/6389922-Mopar_8_3_4_Rear_End_Guide-1.pdf
 
Sdriche said:
And no issues swapping to a 68?
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There are two potential issues that you may run into, but they are not hard to work through....

1. If your car was originally a slant 6 car, the front bolt on the spring hanger is one size smaller... If my old mind can remember correctly, the slant 6 had 9/16" diameter bolts for the front spring "eye" and the v-8's had a 5/8" diameter bolt... You can drill the front hanger bracket out for the larger diameter and go to a good hardware store or Mcmaster-carr for a new bolt.... There's a local Ace Hardware around here that carries the proper bolt for the replacement...

McMaster-Carr


2. Somewhere along he way, they moved the bolt hole for the rear brake hose/splitter... I believe it was for 70 and later (again old mind and bad memory)... We had the wrong one for my son's 71 Valiant swap, and was able to order a custom one from The Right Stuff with 3" more hose length and solved that problem... But I think your going to be ok with a mid 60's to a later 60's swap....
 
Before making that drive, I'd have the owner measure the rear to make sure it's an A-body rear end. 43" center to center on the perches, overall width, small bolt pattern, brake size, etc......A factory 8 3/4 would be very rare in a '65 A-body. I've seem many swapped in, even at the dealer when the 7 1/4 broke under warrantee, but, I've never seen a genuine factory one that year. It's even fairly rare in the '66 models.
 
it was a slant 6 car. Does that mean i have to swap leaf springs as well? I was only only going to swap rears.

krazykuda said:
There are two potential issues that you may run into, but they are not hard to work through....

1. If your car was originally a slant 6 car, the front bolt on the spring hanger is one size smaller... If my old mind can remember correctly, the slant 6 had 9/16" diameter bolts for the front spring "eye" and the v-8's had a 5/8" diameter bolt... You can drill the front hanger bracket out for the larger diameter and go to a good hardware store or Mcmaster-carr for a new bolt.... There's a local Ace Hardware around here that carries the proper bolt for the replacement...

McMaster-Carr


2. Somewhere along he way, they moved the bolt hole for the rear brake hose/splitter... I believe it was for 70 and later (again old mind and bad memory)... We had the wrong one for my son's 71 Valiant swap, and was able to order a custom one from The Right Stuff with 3" more hose length and solved that problem... But I think your going to be ok with a mid 60's to a later 60's swap....[/QUOTE
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cudamark said:
Before making that drive, I'd have the owner measure the rear to make sure it's an A-body rear end. 43" center to center on the perches, overall width, small bolt pattern, brake size, etc......A factory 8 3/4 would be very rare in a '65 A-body. I've seem many swapped in, even at the dealer when the 7 1/4 broke under warrantee, but, I've never seen a genuine factory one that year. It's even fairly rare in the '66 models.
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He confirmed 43" center to center so I should be good. Thanks for the suggestion
 
Sdriche said:
He confirmed 43" center to center so I should be good. Thanks for the suggestion
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If the rear end has been swapped in by somebody at a time in it's life, very common to weld on new perches at 43". What I'd be asking is what is the width from backing plate to backing plate. And is it small bolt pattern. You don't want to pay "A body 8.75 price" for a B-body with relocated perches and is a little wide. I'm in no wise suggesting the rear end isn't original, just say'n before you make the trip...
 
Sdriche said:
it was a slant 6 car. Does that mean i have to swap leaf springs as well? I was only only going to swap rears
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Probably not BUT, you could check the parts catalogue and see what it says.

My 67 dart has the rally package and I have stock 6 leaf springs. I think without it you get 5 leaf
 
krazykuda said:
That's a bold question to ask...

Nunya beeswax
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Reason I'm asking is if he is getting the car and all for 1000 he might be ok if the rear is a rust bucket if he can recoop his losses on other parts from the car. The rust on the rear end alone makes me think that there is no way the u bolts are coming off in one piece and the rest of the housing might be as bad and MIGHT also be full of holes.

I know the folks on the east coast consider anything that can hold itself together to be a A+ part, but there are other areas out there where an A+ part is really an A+ part. (Not bashing east coast folks, it's all you have available)
 
Sdriche said:
it was a slant 6 car. Does that mean i have to swap leaf springs as well? I was only only going to swap rears.
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No, you don't have to swap the springs, but the slant 6 springs are softer than the v-8 ones... It would be a good idea to upgrade eventually....
 
If the 8 3/4 was swapped into the car, maybe the springs were too. If you're getting the whole car, see which set is better.
 
I just bought a "A-body 8 3/4 rear"....need the 8 3/4 shock plates too. Bolted right in to my 65 "S" spec 5 leafs. The gas tank was like 1/4 inch from the dome though, just a "check your ****" once you get it in. Drive shaft needs to be shortened too.
 
Sdriche said:
And no issues swapping to a 68?
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Direct bolt in except the drive shaft has to be shortened and possible a different rear yoke and or u joint. 63-76 A bodies. . DIRECT bolt in. Prior to 63 may even be included, but I am unfamiliar with those so I left them out.
 
Id you end up with a mismatch between the big and little u-joints, you can buy "cross joints" which are big joints one way and little joints the other way so you don't have to swap yokes.
 
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