tranny difference???

[punkr6]

s20 is obd1 92-95
s40 is obd2 96-2000

as far as gearing goes, you need to be car specific. such as ex,si,dx,lx

both ex/si have the same gearing and are shorter then the dx,lx tranny's
performance wise your gonna want the ex,si transmission

fuel economy is a little better with the dx,lx models, but they are garbage and slow as balls.

Hope this answers your question.....