http://www.homedepot.com/p/Class-II...gclid=CJTp2KCDr80CFQ6LaQodqu0Lkw&gclsrc=aw.ds If you mean between the rails, (verses something off the bumper) all the manufacturers have their "universal" hitches.
34" is the same width as Chevy trucks from the mid 50s up to around 1987. So if you find a used hitch off an old Chevy on craigslist, it might fit
I've got a frame mount hitch on my 49 F1. Swap meet item, reversable ends, bolt ons. Unknown original but with a tape you can find one that fits.
Chevy or Ford truck and modify. http://www.ford-trucks.com/forums/1282990-trailer-hitch.html#post13830731
I bought a used hitch from Pull A Part for 25.00.it is made by drawtite and was under a 1985 chevy truck. It fits perfectly. It looks like it was made for my 53 ford truck.