Originally Posted by jlicrx
if you swap the knuckles/hubs (spindles) from a DX or Si, you can use the DX or Si axles (they are the same) - or, you could use the 5 speed transmission with your STD 4 speed axles and leave the hubs you have
the way i was figured it was that both the hubs and tranny have to be swapped in order to use dx/si parts. for example say you have an si tranny and swap on some dx hubs it'll work as well as vice versa, now if you try std hubs with a dx/si tranny or dx/si hubs with a std tranny it wont fit properly, i own a 4spd std so i kinda would kno... i cant remember the exact numbers but i think std has like 4 or 5 less splines than dx and si have on their hubs and trannies.
EDIT: if you really wanna know just pull out one axle and compare it to your si counterpart.