John's prior post with pic and George's description point the way. Finding one at a junkyard is a fool's errand. I have NEVER seen one on a junked car, plus, stock is for a smaller pipe and unless your in the right part of the country, in that location under the car, likely muy rustado. 1/8" X 1"X 1" angle, some grinding and drilling, and the right size U bolt or your clamp will get you where you want to be. Heck, it's small enough - I'm going to make mine out of stainless!
I think if you took a piece of metal 1-1/2" by however long it needs to be and bent it 90º on the diagonal - corner to opposite corner, it'd give you a horizontal surface for the U bolt/clamp and a vertical surface to bolt to the tranny.