1989 gmc/chevy rearend worth?

[modifiedGMC]

I found a truck I'm thinking of buying for parts. It's a wrecked 1989 1500. I was wondering what the rear end would be worth, it has had new seals and bearings installed before it was wrecked, it also has had the flip brackets and looks like lowering shackles. The rear was mounted on top of the springs. I don't know how the front was lowered. the spindles don't look like drop spindles, may have shortened springs. Can't really tell since the front end was totaled. I want the engine and fuel system and a couple of other parts but he wants the whole thing gone so if I get it I was going to part the rest out. VERY FEW body parts are good like tail lights door handles, little stuff like that, possibly the seat, I didn't uncover it all the way and looks like 75% of the "new" dual exhaust pipes also good. Any opinions are welcome.