The 707 700 was a program that called for 707's to get re engined it the late 70's early 80's. The program would replace the old JT
-3 on 707 with CFM 56-2 like the ones on the DC-8 70's and KC
-135's. In a article I readied about the 707, it said the reason why Boeing drop this program was the fact that it could hurt the 757 sells. They had tested a 707 700 but after the program was drop they turned in to a 707 300. Seeing how successful the DC-8-70's and KC
-135 are with the engine and the fact that they still flying today make me thick if Boeing do not drop this program 707 700 would be hauling a lot of cargo today. So did make a good decision or a mistake.