Help identify what this is / was used for...

[bmnk]

So I've finally begun my 50' 3/4ton project, and as I was looking over the truck the other day I noticed something that I had previously overlooked.

I'm not sure if it was something that a previous owner added, or if this was from the factory. Either way I can't figure out what it would have been used for. It might be something obvious, but for the life of me I can't figure it out.

[Russell Ashley]

That was most likely a mount for a mirror. Doesn't look factory to me but that is about where the factory mirror was mounted.

[mknittle]

Aftermarket mirror. And they often bend or break the metal around the base.
On the optional{GM} mirror the screws are farther apart. look under the dash at the inside of the cowl you will see a sheet metal backer with 2 holes in it that is where tha mirrors mount. The passanger side morror was an option.

[mr48chev]

Yep, a big mirror. You can look at those brackets on five trucks and no two of the will be mounted exactly the same on the right hand side. I think they flipped a left hand bracket and bolted it on.

Usually they were on the 1 tons and up and both of my 1-1/2 ton cabs have that bracket.

[sweet70beast]

I agree. The ones I have seen have usually been on the bigger trucks, most of them still had the mirrors and arms on them.