New to me truck

[topdog]

I just bought me a 68 k-20 long bed fleet its a 327 with a 350 auto (was a 4 speed ) I i'd the t-case as a np205. the rear end is a 10 bolt 8 lug full floater. Can someone tell me if this is the stock unit for these trucks? I thought 3/4 tons came with a larger diff's. front is also 10 bolt 8 lug. Here are a couple of pics. I didn't get the front diff. batteries ran out on me. I'm really wondering how strong these are. Any info would be appreciated. Thanks