how would i know if my '90 s13 hatch with a 5spd tranny have an LSD on it?

 

1. Jack both back tires off the ground.
2. Manually turn one rear wheel while watching the other.

If they spin the same way it's LSD, if not it's a standard open diff.

If it's not LSD I have a spare one I can sell you. (supply your own J30 axles)

 

My favorite way, stop in the road tach to 6,000 rpms dump the clutch. Go back and look two black marks, lsd. One mark not lsd.

 

i like your method s13dude! what lsd would be the best for everyday driving and the occasional drifting?

 

check out this thread