What's the difference between the T2 S4 and T2 S5 transmission, driveshaft, rearend, and halfshafts?

I have a T2 S5 driveshaft, rear end, and one halfshaft (other got lost in mail). I'm looking to pick up a trans and axles, but didn't know if it mattered if they were S4s'...

 

The s4 and s5 Tranny's mount differently,so you need the mount for that Trans(if it is s4 use an s4 Mount)
the Diff's are different to,I believe.One is Viscous(fluid) and the other is a Clutch type diff.But they Mount the same and the Shafts are the same IF it is TII(s4 and S5 TII Half shafts are swappable)...N/A and TII differentials are different in size.If you use the diff you must use the axles for that Diff(TII diff.Tii axles.N/A Diff,then N/A Axles.)
The axles(half shafts on a TII are beefier)
You can't put an N/A Driveshaft on a TII,or Vice Versa.You must use the appropriate Drive shaft.the Holes for the studs won't line up at the Diff..A conversion shaft CAN be used if you are Swapping, Say to use a TII Trans and an N/A Diff.(www.Mazdatrix.com Has the Conversion drive shafts).
I hope that answers some Questions.Cheers STYX!~

 

Thanks, you've answer everything I wanted to know.