If you want to go the carriage bolt route, Go to a hitch seller and pick up some "Bolt reinforcing plates & bolts". They are small pieces of steel about 2" x 1" with a square hole in them for a carriage bolt. They only cost a couple bucks for 3 or 4. Most hitches that mount to uniframes (including the KJ) use them and they are cheap. Normally they just drop into the frame and a carriage bolt drops through them locking into the square hole in them. The size/shape of them prevents them from spinning inside the frame. You slide them into a large hole in the frame as described above.

BUT first you attach a piece of safety wire (or other stiff wire) to the bolt (wrap around a couple of threads) fish the safety wire through the hole in the backing plate, then fish the free end of it through a hole in the frame that the plate can fit through. Fish the other end out the hole where the bolt will come through, stick the plate up into the hole, pull on the wire and Voila! The plate goes up into the frame, the bolt pops through the plate and out the bolt hole. Remove the safety wire and thread on the nut. Done!

See the link and diagram of the plates & wire trick (they call it a "leader") below:

http://www.lostkjwest.com/tech/hitch.pdf





Of course you can always go get a piece of threaded rod and bend it into an "M" shape. Some people have commented on the strength (or lack of) of doing it this way but from what I can see from unbolting mine is the fact that with everything bolted up tight, the stress wouldn't be on the threaded rod anyway, it would be distributed through to the frame. Much like the stress that's on a hitch pin when you tow a vehicle. Those pins aren't very thick and the take a whole lot more stress.