some one told me that that means its a posi. unless the gears were welded. correct me if i'm wrong, i'm not to familiar with the differentials.

 

Nope just like 95_318SLT said. You don't have a posi! Just a normal Open diff!

 

IIRC an open diff should spin the wheels in opposite directions when you turn one. turn left wheel forward with the truck in neutral and the right wheel should turn backward. This video does an ok job of explaining. This isn't mine i just stole it from the u toobz

http://www.youtube.com/watch?v=Mt5BJz2vMJ4

this one also helps towards the end he discusses open diffs.

http://www.youtube.com/watch?v=XSRAO...eature=related

Hope this helps!