My drive 26 spline drive shafts and my diff slide together nicely and fit.
However the drive flange doesn't seem to have a circlip groove. I can see the end inside poking out of the splined diff gear, is this going to be an issue? is the suspension travel going to be enough to dislocate the flange from the diff, i can machine a circlip groove into the end but theres really not enough room.

Inboard Sierra push-in CV joints don't have a circlip holding the CV into the differential.

The tripod joint on the outer CV has a cup and spring pushing the drive shaft towards the differential and this is supposed to keet the inner joint engaged with the differential.

ok, thanks. No need to worry then.