71 3/4 K Suburban

[Mr Big]

Yesterday I was looking at a 71 4x4 K Suburban, (thinking about making an offer), But I noticed it had the old Spicer rear under it...like my 66 3/4.
I was expecting a DANA. Is it possible it's original? The owner claimed 4.56 posi?

I know it's an original Fleet orderd truck, white with barn doors, pdisc, auto, rear air, ps...I have to look again at the glovebox sheet.

It's been sitting in the open for many 5+ years, but runs well. It's got some ugly typical rust in the front floor kick panles, mostly from a leaky windshield. The rear of the truck is fairly solid. Not beat up too bad.The guts are pretty well roached. Any idea from the description if it's worth saving? How much is too much? Sorry if the questions are idiotic, I'm not familular with these early burbs. Thanks for any advice/help. Glen