To verify:

An "axle" is the same as a "half-shaft" is the same as what the S5 FSM on page M-14 calls a "drive shaft", correct?

Also, S4 and S5 Tii "drive shafts" are interchangeable, correct?

I searched and didn't find that particular point called out but there was a post that the part numbers changed over time.

Thx,

Jim

 

axels=halfshafts. all t2 are the same. dont have time to look at the fsm right now but i hope you know the difference between an axel and a drive shaft

 

and while be-bopping around eBay saw this
with this warning...

This is for a NEW, complete Turbo rear axle / haft shaft CV assembly. It fits all 89-92 (S5) Mazda RX-7 Turbo II FC3S. It will also fit any other FC3S RX-7 with a 5 lug that's using a the 89-92 turbo LSD rear end.

Comes complete with CV joints. Brand new, ready to install. Perfect for replacing your bad one or to just to keep on hand, as big HP RX7's will brake these often. The picture is of the actual item you will receive.

Note:
This item will NOT fit any car that isn't using the 89-92 RX-7 Turbo LSD. This includes the 87-88 Turbo II. It will only fit if you're using the S5 Turbo LSD Diff.

Seems awfully specific.