Does anyone know how these factory parts(FXR) are made?I know they are pretty sturdy.Thinking they are forged.

 

Generally speaking, forged are stronger. Forged material is stretched towards the point where the material will yield, i.e. break. Yield strength is the area of failure of a given material. The closer to that point the stronger the material is. A forging starts as a heated blank chunk of material and is beat into a mold shaped generally like the finished part. It may take several heating's and molds closer to the final shape to get the end shape. Any machining comes after the forging is done.
Cast is poured into a mold shape and can have flaws in the material. Many cast parts today are cast into a reusable mold and are better looking than sand casting. That is called die cast. Castings tend to break and forgings tend to bend first.
Not knowing what mounts you have, I can't say what they are.