Four dedicated military variants of the FC-170 were manufactured for the U.S. Navy and Marine Corps, under a 1964 contract. Production is estimated to have been between 400 and 700 units, mostly the M677 four-door pickups. A 1963 analysis done by Jeep, concluded that the militarized FC-170s compared favorably to the aging Dodge M37, at least for "behind" the front-line service. The XM-676 prototype had a 50% larger cargo cube, could carry 12 troops in the back instead of eight in the M-37, had a 700-pound greater load rating, and yielded more than twice the mileage, but Jeep was likely more focused on landing the contract for the M-715 trucks that replaced the M-37.