In the episode where X-Bomber rescues the 'defecting' Termoid 1701 the astrofighter that X-Bomber protects is significantly different to the ones chasing it. The latter ships are standard fare. However 1701's fighter is black rather than green, has larger engines, a gun that is mounted from a central pylon under the fuselage pod rather than connected to the engines. The ship also has two very noticeable intakes either side of it's fuselage infront of the wings.It's still not as developed as Carter's Astrofighter, which appears later in the episode, and which I think changes from one shot to the next as it is more than one model, as parts of it come and go as the battle progresses. Upon close inspection; Carter's fighter literally has twice as much everything as the standard ship.It has 2 little boosters on each wing rather than 1, a cockpit mounted in an extended nose cone, a sort of intake (starboard) and a second cockpit (port) where the cockpit 'should' be, much larger engines and wings, a sort of buoy towed behind the ship and lots of extra wiring on the hull.
Dream big and bold and daring.