89 shafts or can I just swap out the ones in my civic dx to my 89 si tranny.Thought I read something about 20 and 21 splines somewhere.Thanks

 

^^^^^^^^^^

 

im not completely sure, but im about 99% sure that the axles will work, its the clutch disc that will not work

again, im not completely sure about the axles but im sure that you need a new clutch disc from an 89+

 

DX and Si axles are identical, its the HF and STD axles that have smaller outer joints. You should be fine swapping axles. However, since you tranny is from an 89, you need an 89 clutch as you 88 one wont work.