A little P/S bracket i.d. help...?

['69 C10]

I picked up some extra parts in a recent purchase and am trying to determine the engine that these p/s brackets go to. The gentlemen I got them from said they were on an Inline 6 and he thought it was a '67, but that was really just what a previous owner had told him.

I've looked through a lot of pics from related posts on the forum, but still haven't found these exact pieces. Seems to me these are just 2 of 3 necessary brackets to make it work...

Many thanks for any insight!