Tommy,
I converted my Williams E7's to KD's both front and rear. On the front, I also cut off the truck pilot and fixed it to the chassis with a spacer plate. I then mad a shim out of Plastruct and mounted the KD pocket to it. On The rear, I removed the lobster claw and fabricated a bracket that mounted to the existing hole on the truck that held the original coupler. I mounted the KD pocket to that bracket and simply bolted the assembly back onto the truck. That way, the coupler would swing with the truck. I have since removed the rear KD because I sold that engine (but I still have another) and you are welcome to it. It is a simple bolt on. You can contact me through my e-mail in my profile.