I've got an answer that will clear up some of the misconceptions posted in this thread.
First, Ford did not produce jeeps under contract from anybody but the Army's Quartermaster Corps. Willys won the contract on price just like everything else. It certainly helped that they had a more powerful engine which is most likely the reason that their entry was not immediately disqualified for being overweight.
Henry Ford, being the contrary sort that he was, said, "Ohhh, hell no!" or whatever the equivalent of this was in 1941. Ford's factories were producing bombers, tanks, trucks, and all sorts of vehicles for the war effort and Henry was determined not to be left out of the 1/4 ton reconnaissance car market. So his sales people went back to the procurement offices and pointed out that Ford had factories everywhere; Willys-Overland had one. Sabotage, union strikes, material shortages, transportation problems, or--God forbid--the war coming to our shores could certainly hamper Willys' ability to produce the needed number of vehicles at their one factory. (Let's remember here that Willys-Overland--like a lot of car builders of the era--was more of an "assembler" of parts than a complete manufacturer. Ford had foundries, stamping plants, steel mills, design studios, upholstery shops, and even a Brazilian rubber plantation. Which one is more likely to be screwed when a distant supplier is burned to the ground, bombed, sabotaged, suffers a work stoppage, or has a supply line cut by an enemy advance?)
The procurement officers were convinced, especially when demand far exceeded what Willys could produce in Toledo, and Ford won a secondary contract. While Willys and Ford both continually built jeeps throughout the war, Willys built every one of theirs in Toledo, Ohio. Ford built theirs in plants all over America, including Richmond, CA; Dearborn, MI; Dallas, TX, Louisville, KY; Chester, PA; and Edgewater, NJ.
GP (Ford's prototype) and GPW (Ford's production jeep) do not stand for General Purpose or General Purpose Willys.
In Ford's nomenclature of the time, G stood for a government project. P is for an 80 inch wheelbase reconnaissance car.
When Willys' design was chosen as the "winner" and Ford received their plans and patterns to make theirs exactly like and interchangeable with the Willys MB (Military model B), the W was added to indicate that this was built to the Willys pattern.
Ford also built the GPA (A for "Amphibious") and the GPB (although the "Burma Jeep" is more of a truck--lighter than the the 2-1/2 ton--for use on tight winding mountain roads in the Pacific theater.)
Ford did have one more contribution to add to the overall design of the jeep, though. Clarence Kramer at Ford had designed a one piece stamped radiator protector that was lighter and much cheaper to produce. After building roughly 25,000 MBs with their welded together, heavy, slat grills, Willys was ordered to switch theirs to the Ford design which featured 11 vertical slots to allow air to the radiator. From then on, with the same grill design, it became very hard to tell a Willys MB from a Ford GPW from more than ten feet away. And now you know why jeeps still have a Ford grill in them.
Sorry for going overboard with the history, but the "General Purpose Willys" myth must die!
