chevy 12 bolt rear

[chevy821]

whats up i have a 82 c-10 short bed.with a stock 12 bolt singel leg rear i am pretty shore its a truck rear. what i woul like to know is how to find out if it is that an info on how to make it a posi such as what type of unit to get an what an axle lengh. any help would be great

[Captkaos]

Not sure what this means:

what i woul like to know is how to find out if it is

But to "make" is a limited slip, you buy a new differential and have the gears setup on it and reinstall.
there are no axle length options, you don't need new axles unless what you have are broken.