Hello every one
my Q is what  do I need to change in my rear end to go from a limited slip to a positive traction  

Ummmm...limited slip is posi trac.

Different levels...

Open differential: power is delivered to one wheel

Limited slip: power is delivered to both wheels unless turning (in which case the different wheel speeds of the inside and outside wheel cause enough of a torque difference to allow the clutch plates to slip).  Usually done using clutches or cones or other wear surfaces.

Locker: power is delivered to both wheels at all times...regardless of whether or not the car is turning.  Usually done by welding spider gears together (NOT recommended) or using a spool.  

Limeted slip and positive traction are terms used by the manufacturers to lable their traction control devices. Powertrax company makes a locker conversion kit that maybe what your looking for and it won't turn the rear into a spooled type rear where you would have no differential at all.