So why? Boeing made 707 and then they built 727. Why not 717? Does the plane called 717 ever have been on-project? Why 717 built only now, after 777? Does they leave this name for something? Or there WAS old 717 between 707 and 727?
THe 717 was Boeing's type number for the basic C-135
design. The C-135 has a narrower fuselage because it is more closely based on the prototype 367-80. The 707 was originally to have 5 abreast seating. This was changed to 6 abreast before the final 707 shape was finalised.