Such as Auburn Gear or Zexel Torsen? 1994 Z28...

 

I believe if it is the OEM factory posi unit it will be an Auburn clutch-cone type. If someone has changed-out the unit, you'll just have to remove the cover take a photo (that shows the inter-works of the carrier) and post it here and let someone ID it.

WD

 

The Auburns have yellow springs in the clutch pack, very easy to see if you pop the diff cover off.

 

I believe that the Zexel Torsen diff's weren't used until the late 90's (~'99? ) so I'm pretty sure that all LT1's came with the Auburn .