Is there any way to find out the difference between a Y1 S1 or a YS1, is the a number or some kind of marking?

 

There should be a sticker on the tranny housing that says y1,s1..but anyone can swap the internals.

Brad

 

basically 90-1 cases are different from 92-3 YS1

first difference is that 92-3 case is larger + it has a front mount (meaning 4 mount point) not 3 like on the Y1. also YS1 can be LSD if its JDM while S1 will usually not be, Y1 can LSD

another JDM b16a tranny is a J1 (same as S1)