Assuming that you could fit it in, an Avon would certainly make a Vampire travel very rapidly. See Wiki data below.
Goblin:-
General characteristics
Type: turbojet engine
Length: 107 in (2,700 mm)
Diameter: 50 in (1,300 mm)
Dry weight: 1,550 lb (700 kg)
Thrust :3,000 lbf (13.34 kN) at 10,200 rpm at sea level
Avon:-
General characteristics
Type: turbojet
Length: 126 in (3,200 mm)
Diameter: 35.7 in (907 mm)
Dry weight: 2,890 lb (1,310 kg)
Thrust:-12,690 lbf (56.4 kN) dry, 16,360 lbf (72.8 kN) with reheat