 The transmission, driveshaft,...  The transmission, driveshaft, and differential all have to be at the same angle. SAC used a digital level to dial in the correct angle of the rearend (5 degrees). |  After tack-welding the rear...  After tack-welding the rear crossmember while on the horizontal plane, SAC's fabricator finished welding the crossmember in place by C-clamping the frame in the vertical plane to the sawhorses, thus ensuring all surfaces were fully welded. |  Notice the radius rod support...  Notice the radius rod support has already been welded onto the bottom center crossmember. Herb finished welding the pinion-support anchor onto the side of the frame. In order to locate exactly where these tabs go, Herb had to mock up the IRS first and make sure the two radius rods would be at the same angle, and the two pinion support rods at the same angle. |
 Herb marked where the C-notch...  Herb marked where the C-notch should be on the four framerail sides. |  To cut the C-notch openings...  To cut the C-notch openings in the underside of the rear framerails, he used a plasma cutter. |  Prior to welding the C-notch...  Prior to welding the C-notch openings closed, Herb wielded his electric grinder and air sander. |
 Since the rear framerails...  Since the rear framerails have been fatigued from cutting holes in them for the C-notch, SAC welds in a 1-inch thick metal splint to strengthen them. |  To achieve the desired curve...  To achieve the desired curve of the sheetmetal that would cover the C-notch openings, 10-gauge sheetmetal was bent around a 6-inch-diameter pipe. |  erb cut the C-notch filler...  erb cut the C-notch filler pieces to size in the bandsaw, before sanding the edges smooth. |