Has anyone swapped a rear disc brake setup from a 1975 C body with 9 1/4 rearend to a B or E body with 8 3/4

It can be done but the replacement parts are expensive and hard to find..

There was an article YEARS back on this.
Even then, the word was that parts were too hard to find.
Considering that there are now kits, it would be smarter to sell off the stuff if you have it and get something more serviceable...

The 74/75 Imperial are the only ones that had rear disc brakes,not easy to find.The calipers are not a problem as they are 70 and up A-body,the emergency brakes are a complete assembly with another set of small shoes that goes inside the rotor,extremely hard to find,better to use one of the current upgrades if you don't mind spending the money.

I thought the rear calipers were like slider 73 up calipers. Not the four piston KH 66-72 calipers.

I would think you could find a speciality place to reline the parking brake shoes if necessary (wouldn't think they'd wear much).

I know a couple people that have put them on 8 3/4 rears. You have to use green bearings and only used 4 of the 5 backing plate bolts. Also you machine the caliper adapters to move the caliper over some. I can't remember the amount but something under 3/8".

I though the disk were really hard to come up with??

I thought...
I thought...
You gotta do this...
You gotta do that...
If..
But...

You're obviously looking for an easy way to put disks on your rear axle. This is not the way to do it. It's a dumb way.

This is the reason i know how they work !

Even I wouldn't do that swap and I have the ability to make just about anything!

If you want rear disc brakes (you probably don't need them but maybe that is beside the point) then get a kit from Cass.

www.doctordiff.com is the address.

I'll bet ya that by the time you're driving down the road on your new Y-body rear discs you could have just bought a new (better) kit from Doctor Diff instead. I thought about this idea too, many times. It never seemed like the way to go. Maybe if we were in the 70's still...

i picked up a set off a 2001 dodge van 1500 9.25---they will bolt onto any other 9.25 8.75 will just have my axle guy index the 5 on 4.5 pattern-----parts are really easy to find--pickapart price $80....bob