I'm not familiar with import from Revit settings, but you may check the scale even when the models already imported in 3ds Max - select your model, then in command panel, go to utilities tab and open measure panel. There you will see object's dimensions. Next, change your gizmo to select and observe it's scaling factor in transform type-in window. If the scale is not 100%, you need to reset your object's transforms - command pannel>utilities>reset xform.