Are the zuki output shaft flanges interchangable on the rear 3rd members?  I bought a larger bolt pattern (later it seems) rear chunk and swapped it in my 86.  Little did i know the pattern was different.

The flange came right off the old 86' unit.  I cannot get this newer one off with a slide hammer the same.  I stopped to add this post just in case I was doing something wrong. TIA

they will but look at the splines  some are /\ and others are \_/

I noticed the retaining nut was 2 piece with a washer, and 1 piece on the other.


And correct if wrong but remove the nut and use a puller to get it off?

...the other thought was to just use the back driveshaft from the later unit?

Swap the rear driveshaft - you can get yourself into problems with bearing preload and the gearset mesh if you swap the flange.

Some flanges will slide right off and others are harder than hell to remove.  Yeah, just remove the nut, or the nut and washer, and the flange should come off.
There are spline differences, as fordguy79 mentioned.  The way you tell if the splines are the same (without removing the flange, or even the nut), is to look at the outside of the flange.  The flange will either have a slight groove all the way around it, or it won't.  As long as they both do, or don't, then they are the same spline type.
You can just use the rear section of a large bolt pattern driveshaft, instead of messing around with the flanges.

You could just swap the driveshaft flange, change your u-joint while you are at it

Wild

thanks all.  I ended up swapping driveshaft flanges along with 2 new u-joints.