Abstract: An automotive body framing system includes a clamping frame assembly for accurately positioning and clamping loosely assembled main body panels and header members in accurate alignment with each other to be welded into a rigid permanently assembled relationship. The loosely assembly panels and members are mounted upon a conveying sled upon which the floor panel of the assembly is accurately located. A clamping frame assembly including front and rear frame sections pivotally connected in end-to-end relationship with each other is movable into a clamping position overlying the body from front to rear and supported in an inverted V configuration by support posts which support the front and rear ends of the frame assembly. Clamps mounted on the front and rear frame sections are actuable to clamp the various components in accurately assembled relationship to each other while leaving the entire opposite sides of the body accessible to welding devices.