Is there an easy way to identify an S4 Trans from an S5?

 

Gearing.

 

from what I've read on the forums everyone seems to say that the parts are interchangeable except for the mount. The reason I ask is I was going to order a clutch kit from RX7 World and they had 2 options... 86-88 and 89-91... I've read on the forums that there was no difference and was confused as to the two options for the clutch kit.