CJ4

The CJ4 proto-type.

It is said that there were only a few CJ4 were ever made, which too were proto-types. It was never put to full production and a hence remained unknown to a lot of people. It was said to have been made in 1951-52 and was mainly made keeping the military in mind. The project never saw light and was scrapped by the Willys Overland company.

It is said to have the "Hurricane" engine, which was a proto-type then (1951-52),  also put in the CJ3B, which came in 1953. It also had a T-90 gearbox, Dana transfer-case and Dana axles. It is said to have had a high bonnet which was curved, resembling the CJ5 which came out later.

The High bonnet which was curved like the CJ5

A military CJ4

There are rumours that it was a experimental Jeep made for the U.S. Army, but somehow the Army didn't show interest and the Jeep wasn't made. There are no fixed numbers suggesting how many were made, some say there were only 2, some say there were even 200-300. 

There are no exact  specifications known about the CJ4, but it is said to have a high bonnet, which had a curved body style of the later seen CJ5.