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8.75 question (64 polara)

dukeboy_318

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I have a 64 polara with the 8.75 rear. I know there was something different about the 8.75s from that year but I'm drawing a blank as to what. so my questions are:

1: What is special about 8.75s from that year?

2: I have a working spare 489 suegrip from a 8.75 with 3.23s, the current carrier has an open diff, will the differences in the 875 still allow me to swap in this 489 pumkin?
 
I'm not 100% sure but I believe the axles were tapered in the earlier 8.75's maybe @Cranky can school us here.
 
There is an interchange problem with differentials and axles manufactured prior to 1964 (See Part II, Section 1: "Thrust Block Variations").
http://www.mymopar.com/Mopar8_75RearEndGuide.htm
I have very little experience with the older (pre 66) 8 3/4's but this has been talked about just not too long ago here. Only problem you might run into is something that was early 64 and the factory was still using left over parts to get rid of them. I've ran into things like this in other areas where there is an overlap of the old and the new stuff between years...
 
The centers will change without issues.
 
I have a 64 polara with the 8.75 rear. I know there was something different about the 8.75s from that year but I'm drawing a blank as to what. so my questions are:

1: What is special about 8.75s from that year?

2: I have a working spare 489 suegrip from a 8.75 with 3.23s, the current carrier has an open diff, will the differences in the 875 still allow me to swap in this 489 pumkin?

The "pigs" all swap but the axle shafts are longer in open rear ends. The axles can be shortened (cut/grind) to obtain proper end play with sure grip differentials.
Mike
 
The "pigs" all swap but the axle shafts are longer in open rear ends. The axles can be shortened (cut/grind) to obtain proper end play with sure grip differentials.
Mike
Hmm, I've not ever ran into that before. Is that just for 64 era 8.75s or all of them?
 
The "pigs" all swap but the axle shafts are longer in open rear ends. The axles can be shortened (cut/grind) to obtain proper end play with sure grip differentials.
Mike

No, he has a 64 rear. Same axle widths for open and SureGrip center sections. Different axle widths on '63 and earlier because of the thrust block sizes between open and SG centers.
1964 still had tapered axles though, last year for them in a B-body.
 
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