Idenifiying 68 c10 12 bolt rearend

[casey86cuda]

Hello I,m new to the 67-72 chevy trucks so I,m just learning about them I,m A mopar guy restoring 68 3/4 ton camper special for a customer and just bought a 68 c/10 for parts.The 68 c/10 has option trailer over loads radio delete 12 bolt rearend truck was special odered with A/C it has 307 with 2 speed powerglide .My question I what to recoupe some of my cost is the 12 bolt worth anything ,is it worth more if its posi,it also has 2 speed powerglide I,m only using truck for parts so I will have a/c parts if anybody can use these parts .I don,t what to get rich just don,t what stuff laying around any help would be appreciated.Thanks Shawn