wondering what this axle is doing under my truck

[spencer_41188]

so i pick up this craigslist find its a 1980 gmc sierra grande. at first glance its a cab and chassis being so long for a straight cab but wate thats a full width dually someone must of swoped something and no the frame is not streached

im just wondering what it is i know its a dana eather a 70 or an 80 but the dana 80 didnt exzist till 88?

[Lobie]

Anything stamped on it?
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[donut]

What makes you think it's not a 70?

[spencer_41188]

i really dont know what it is alot of stickers are missing i assume it is a cab and chassis and they swoped the 14 out for a 70. all i was worried about is the dana 60 and the np205 out if it but dont worry this puppy isnt going to the scrap yard its getting converted to 2 wheel drive and im gana mid mount that big block 454 lol and streach a bed to fit

[wwj75c30]

id buy that dana 60 if you were closer lol and looks like a 70like my 75s

[gchemist]

Definately an '80. The light bezel insert is a give away. It's the transition year to '81.

[hatzie]

A lot of the dually trucks had Dana 70 axles.

[86454k30]

I am pretty sure that is a dana 70.

[special-K]

Man,lots of C30/3500s around. Not many K3500 dual wheel cab & chassis Sierra Grandes,for sure. That was an exceptional truck when new. Surely ordered by or for a true truck lovin' guy. It's a shame to see one like that altered into something else. And yeah,that would be the Dana 70 rear.