Link to sourceThe Boeing 737-700C is an interesting aircraft. What makes it unique is its ability to convert from passengers to cargo depending on how the airline wants to use it. If you have heavy passenger flow during the summer, but more cargo during the winter, being able to convert between the two is quite helpful.
What also makes the 737-700C unique is that, like the Boeing Business Jet (BBJ), it has strengthened wings, different than the standard passenger 737-700. When in passenger configuration, the plane can hold 120-140 seats and fly 3,205nm. In an all-cargo set up, it can haul 40,000 pounds and fly 2,880nm.
Link to 2nd sourceFor passenger operations, the 737-700C can carry 140 passengers, while for freighter ops it has space for eight 88″ x 125″ pallets on the main deck (with a built-in loading system) and 966 cu. ft. of bulk volume in the belly. The aircraft can load up to 40,000 lbs. of freight.
Would it be possible to allow the FSAirlines 737-700C to have up to 140 seats? All while maintaining the side cargo door for the maximum package size of 4,409 lbs.