I'm using a Dodge AAM 9.25 axle from a '07 Ram 3500 with all the factory mounts removed up front. I chose a front-link-and-coil, rear-leaf-spring suspension just like a new Dodge truck because of the ride quality and load-carrying ability but with our own link design. We put the axle at full compression centered under the frame and made sure it wouldn't hit the engine. Notice how the 6.0L oil pan has a convenient recess above the axle centersection. It is always best to build your suspension with the axle at full compression. This helps ensure against metal-to-metal damage under full-throttle romping.