I recall that different engines called up in a ship scripter actually made the ship it was installed on handle different. It also had an effect on power availability.
Just an example here:
The starflyer engine vis-a-vis the Titan engine. (Agility and power available)
A Liberty Cruiser engine vis-a-vis the Reinland Cruiser engine. (top non-cruise speed)
A Fighter engine vs a Battleship engine. (top non cruise speed, power availiability and manuverability)
AKA Retread
"Where WAS that jumphole from the other run?"