This “built for mud” CJ6 is now on eBay.  The description includes:

This Jeep started life as a Keiser CJ6, It has been heavily modified to be used as a mud dragger. The rear half of the frame is the original that has been boxed and platted, the front half and the rear swingarms ar made out of 2x6 tubing. the axles and transfercase are out of a 1970 ford 3/4 ton truck. The front is still an open diff but the rear has the spider gears welded. The tub is original sheet metal with a 1” square tube frame. The rear of the body has been chopped 20”, and re-made out of sheet metal. The floor is sheet metal and has been raised so the tub would sit low. The winshield frame is rusted out. The front is a galvanized postal jeep clip that has been stretched 24”. I have the hood for it but it has never been finished. It has a fuel cell electric pump and regulator. Five point harnesses. The roll cage is connected to the frame at seven points. The tires are 14/35-15 on 15x8 rimes with a 1 1/2” backspace. The wheelbase is approx. 125”.