Below is the history of the CJ-6, from Wikipedia.
Production: 1955-1975
Engine(s): F-head 4 cylinder, Perkins Diesel, 225 CID V6 Dauntless, Iron Duke I4, 304 CID V8
Wheelbase: 101 in (2565 mm)
The CJ-6 was simply a 20-inch (508 mm) longer-wheelbase (101 in) CJ-5. Introduced in 1955 as a 1956 model, the CJ-6 was never very popular in the United States. Most CJ6 models were sold to Sweden and South America. The U.S. Forest Service put a number of CJ-6 Jeeps in to use. American sales ended in 1975. Just 50,172 had been made when the series went out of production completely in 1981. (Production ended in 1975 for the U.S., but continued in other countries.)