Is it possible to put a 3d object into a gui box?

If this is possible how could I do this? If it helps for you to know what I am trying to accomplish is for it to be when I open up my inventory and try to craft a weapon in one section I want the player to be able to see it as they change values such as the hilt or the blade. Any help will be appreciated!

What you can do is position a 3D object in the center of frame. It is still a 3D object, and if you are using a perspective camera, you will have the potential perspective issues with centering it in the box. You can mitigate the perspective distortion by using a narrow field view and adjusting the world object’s size accordingly.

So if you have a Rect used to place the GUI.Box:

  var rectBox : Rect = Rect(300,300,200,200);

Then you can use it:

 var pos = rectBox.center;
 pos.y = Screen.heigth - pos.y;   // Convert from GUI to Screen
 pos.z = distanceInFrontOfCamera;
 pos = Camera.main.ScreenToWorldPoint(pos);
 worldObject.transform.position = pos;