Years ago, we transplanted a heater from a Hiniker tractor cab into an old AD farm truck my Dad had. It wasn't intended to be anything fancy--just a means of getting some warm air into the cab. But if I recall correctly, it was just a small square unit that didn't take up a lot of room. I think we just bolted it up under the dash in the usual spot and ran the heater hoses to it as usual. My brother works for Hiniker, so we were able to get it REAL reasonable!!
Don't know if this is of any help, but just thought I'd throw it out there.
