I found the engines in the 727-200 and 727-200F were underpowered. I increased the engine power from 15500 to 17400 in the aircraft.cfg for them both. As shown here:

[TurbineEngineData]
fuel_flow_gain= 0.003
inlet_area= 18.000
rated_N2_rpm= 29920.000
static_thrust=17400     //15500
afterburner_available= 0
reverser_available= 1
ThrustSpecificFuelConsumption = 1
AfterBurnThrustSpecificFuelConsumption = 0

Mark