It comprised the following four variants :
The name "M-5-6-318" stood for "M"ilitary-"5"000 pounds payload-"6"wheels-FCB-"318"B 6-cyl. engine.
However, as the price was 20-25% over that of the competitive GMC CCKW 352/3 design, the QMC decided to standardize to the latter and furtheron reserve the M-5-6(x4)-318 for foreign aid, mainly to the Soviet Union and China.
The 500 Ft.Wayne-built trucks (W-460525 to W-461024) were subsequently sent to the Soviet Union thus being among the first 3-axle trucks received by that ally.
Some 3,000 M-5-6x4-318 more would follow...