Front Upper Shock Mount Question

[Nitroblood]

Before I bought my C20, I took it for a drive a heard some pretty hard banging from the front end, I figured it would be as simple as a shock or spring change, something of that nature.

Upon closer inspection, the bushings from both of the upper shocks were GONE! Amazed at that, I set out to find a same sized shock on a C10/C20 in a yard with the shocks still intact. PAYDIRT!, or so I thought, I found a set with good bushings, instead of removing the shocks, I figured removing the bushings to be easier.

Anyway, here comes the question, I Threaded Off a nut to free up the shock. When I got home, I realized I didn't have the same upper shock mount set-up. It's like a rod, no threads, coming off the frame with a flat washer type end on it, (I hope someone can picture this) now I'm confused.

Are there two types of upper shock mounts? Thread and unthreaded? Any help or pointers or ANY kind of information would be greatly appreicated. Thank you.