F1/F100/F150 is a series of Ford truck. F1 through F8 came out in 1948. It was upgraded to F100 through F800 in 1953. And again later to F150 through F850. The numbers 1/100/150 are for small 1/2- 3/4 ton pick ups and the numbers go higher as the load capacity goes up, along with the engine size.