rear upgrade

[cowboy4x4n]

would I need to shorten my driveshaft if I switch from my 8.25 rear to an 8.75 rear in my 69 charger.

Thanks

[cowboy4x4n]

Also this 8.75 has this axle nut and castle nut on both sides.  Is this typical of an 8.75 or is an axle swap due to the axle being under a trailer now.  Someone used the 8.75 for a pickup bed trailer

[Budnicks]

That looks like an AMC 8.750" with the castle nut, don't quote me on that thou...

[cowboy4x4n]

Here's more pix.  Measurements and chunk number seem to match.  R amc 8.75 similar

[cowboy4x4n]

More

[Budnicks]

the 741 carrier looks like a regular early pre-1968 8-3/4"

[cowboy4x4n]

Width seems to be b body 44" springs and just over 60" overall

[cowboy4x4n]

Imnat a loss I've never seen the axle ends like that.  Also will swapping to an 8.75 from and 8.25 require driveline shortening

[cowboy4x4n]

well I think i figured it out.  the castle nut is from tapered axle shaftes pre 65.

[cowboy4x4n]

any ideas guys if i need to shorten my driveshaft

[FLG]

Yes you will, or find a correct size driveshaft.

[cowboy4x4n]

ok thank you for the help

[Cooter]

A word of caution. If you've ever seen the axles in one of those rears, you would think twice about the swap. Those axles next to a 1966-up 8 3/4 rear look like Tooth picks next to telephone poles.
If you've ever tried to get the drums off.... BIG PITA, even with the "Special puller"....
All but junk IMO, that's why it's under that trailer. Also, that rear's axle end play is set up with shims, NOT spanner nuts like the later ones. The shims are NOT readily available.

Tapered axle is on the top.



Differences in size of axles as far as seals/bearings. Tapered is on left, 1968 RoadRuner 8 3/4 axle on left.

[cowboy4x4n]

thanks for the advice i passed on the axle when i researched how big of a pita it is