wiw 8.75 rear end

i have a chance to get a 8.75 with 4:56 sure grip out of a 71 road runner. it has super stock springs, new brake shoes, drums and lines. those were all brand new parts 5-7yrs ago. that is the good now the bad, the car made about 10 passes and then parked outside. the car has been moved from time to time by being pushed because the engine has been out of it since it has been parked. so, what would something like this be worth?
i am thinking of installing it under the brown magnum i have.
he also has a rear diff asm out of a srt8 jeep that is a 3.92 with electric diff lockup and complete rr bremo brake setup.
Author: rl73